Let's see if I can beat Psion Backgammon on highest level then

[ParadigmShifter]

So I hit back with any 5 (11/36 chance), 14 (2/36), 23 (2/36) = 15/36. If I don't roll a 5 my blot in inner board is vulnerable if he comes on with a 4, but I have to hit if I can, otherwise I will lose.

If he advanced his other checker forward 3 (H-E, K-I) his blot is 3 away so hit with any 3 (11/36) or 21 (2/36) for 13/36. So I think it's bad - I need to hit though otherwise it's academic lol.

It's academic, I roll 6-4. So I need to run, now have to decide whether to run with both or run with just one.

Gonna have to count the pips now as well I think to make that decision.



I make my pip count 51 before taking the 10 so 41 afterwards.
CPU pip count is 35. So CPU is ahead. So I probably want to only run with 1. Although CPU has a lot of checkers on its 1 point so it's gonna waste a lot of pips bearing them off so maybe not...

I think I am still better off keeping as much contact (i.e. distance between CPU and me) as possible though so I'm gonna run twice with one checker. GNU will tell me at the end whether that was wise.

CPU rolls a 11 that's good for me.



May as well see what I roll before doing more maths. I roll 44 so can't hit. 44 is a good roll though 16 pips.



My pip count is now 35. CPUs is 31 so it's ahead but I have borne off 2 already so I'm still in this. If either of us roll a big double it's all over though.

[ParadigmShifter]

So it's just a straight race now. No point me counting pips unless CPU doubles, since I can't double.

CPU rolls 53 and goes G-D D-off. It had a choice there could have moved G-B C-off. Probably right to take off the highest point? GNU will know later on

CPU has 1 man off.

I roll 4-2 gonna do R-T, U-off



I'm gonna need to roll a 5 and a 4 or higher really CPU looks like it will likely get 2 off per throw now unless it gets a 21. A double will be winning for either side I think.

[ParadigmShifter]

So it's just a straight race now. No point me counting pips unless CPU doubles, since I can't double.

CPU rolls 53 and goes G-D D-off. It had a choice there could have moved G-B C-off. Probably right to take off the highest point? GNU will know later on

CPU has 1 man off.

I roll 4-2 gonna do R-T, U-off



CPU then rolls 22 and clears its 2 point

I roll 21



I'll take off from my 2 and 1 point. Expecting CPU to double now...

[ParadigmShifter]

Yup, CPU doubles to 8. Let's see



CPU has 10 checkers to bear off, I have 10. CPU pip count is 16 to my 26. Each roll is worth about 8 on average and it's CPU to throw if I accept the double.

Don't think I want to lose 8 by accepting the double, putting CPU on 10 if that happens, gonna have to resign again

I could get a miracle CPU rolls 12 or something and I get a big double, not very likely though.

Maybe I should take a snapshot here and see what could happen (although it cycles random numbers while you think so snapshots don't have deterministic RNG for this I think?). Might be fun to see though.

I take a snapshot and resign.

CPU leads 6-1



I think the CPU was a bit lucky there tbh. When I rolled a 65 to leave 2 blots in inner table when bearing off was the killer, that was a terrible roll by me. Anything else I probably would have won I think.

If you want to see me play out the snapshot to see if I could pull off an unlikely win from that position I can of course Won't count obvs.

EDIT: Gah I thought I had more than 10 checkers (I know I did type that I had 10 though lol) maybe it was worth accepting the double there. Position wasn't as bad as I thought, all those checkers on CPU 1 point means it would waste a lot of pips. It would still have probably got 2 off a turn though and I needed to roll 2 5s or higher so I think it was probably right to resign there. I think rolling 21 after opponent rolled a double tilted me a bit though lol If I had 9 checkers left I might have carried on.

Gonna not play any more backgammon tonight then if I am tilting! It's still perfectly possible to comeback from 6-1 down in backgammon in a match to 11. Just need to get a few wins under my belt.


Match score after 3 games

Me 1 - 6 Psion Backgammon (level 4)

[ParadigmShifter]

That was the position immediately before the game swung. I rolled a 56 and was forced to bear off from S and T points (I couldn't move a 5 on the board since X (the 1 point) was occupied by 2 CPU checkers. That's what you hope for if you have a point in your opponents board when they are bearing off! Which is why you want to hang back if you are losing.

You can't bear off any piece other than one on the 6 point if you have one there (i.e. you can only bear off a checker with a higher roll than needed IF all spaces with that number or higher are empty), which is why that move was forced. Rolled a 6, force to bear of a 6. Rolled a 5, couldn't move from my 6 point to 1, so had to bear off the 5. Very unlucky roll that.

[ParadigmShifter]

LOL played out the snapshot... rolls were (after accepting double to 8)

CPU: 54 C-off x2
ME: 61 T-off X-off
CPU: 41 C-off A-off
ME: 44 lol T-X x2 V-off x2 (Think that's not correct transcription but moves were forced anyway, and it's beer o'clock sorry). Anyway, this was position afterwards:



CPU: 65 A-off A-off
ME: 11 X-off x2 W-off



CPU: 32 A-off x2
ME: I win if I don't roll a 1. If I roll a 1, I lose. So I win from here 25/36 times = 69.44% EDIT: I actually would win with 11 too so it's 26/36 chance = 72.22%. So I'd probably double to 16 here to make this the last game regardless if accepted - CPU would surely resign that though so it would be 9-2 to me anyway? Probably didn't have to roll is what I was saying. Although CPU does not know the match is up to 11 so it may have accepted I suppose? I should have tested that but I didn't



Arsecheeks lol

That was too lucky though think I was right to not play for 8 points and rely on something like that happening.

It's still 1-6 to the Speccy

EDIT: Anyway that's how (modern) backgammon programs decide what the winning chances are... takes "snapshots" of a position and does "rollouts" where it rolls out the game a bazillion times and sees what would have happened.

I'm not going to do the GNU analysis of this game yet.

I could input the moves into GNU whilst playing the Speccy so I could do instant after game analysis which would make it easier. And then I wouldn't have to work out the pipcount I would know it at all times. That's not like "over the board" play though so I won't do that.

EDIT2: I was right about CPU was likely to get 2 off a turn there so I would have needed to bear off 10 men in 4 turns (which I did in that snapshot!), so I needed a double and I had to rely on CPU not getting one. So I probably should not have accepted the double even if I only needed to bear off 9 I think. I think I made the right decision to drop the cube.

When I run it through GNU backgammon analysis tomorrow it will tell me if I was right to do so anyway.

[ParadigmShifter]

GNU analysis of that exciting game is in




It doesn't think the CPU should have doubled first when it did. It had a 55.9% chance to win. I was right to take.

When I redoubled (was going to do it turn before as well), it thought I was too good to redouble and CPU should have dropped.

Final redouble at the end CPU had a 74.8% chance to win so it thought it should not have doubled there, and I was advised to take the double. I'm not so sure about those odds myself lol! I think dropping was fine given match situation.

I'm not so sure really although I messed up the match score situation in GNU before I started (set it up to start at 1-6, score at the end) rather than score at the start (1-2) and it takes into consideration that so maybe it's advice might have changed if I had got the score right lol.

I made 2 "very bad" moves vs. CPUs 1 (one of my very bad moves was bearing off at the end, so need to study that a bit more). We each made 1 bad move. EDIT: Nope, CPU made 2 bad moves. Bad moves are blue. One of those was my very 2nd roll, GNU thought I should have set up a blitz and hit in my inner board, so GNU plays very aggressively looks like. I did have a lot of men in the blitzing zone though so I should have considered that.

EDIT: That was my risky slotting move. In hindsight, since I was taking a risk anyway and leaving a blot in my inner board, I should have hit so CPU could only take 1 other move if it came back on, and it might have danced anyway. So if I was going to take a risk (which GNU recommended) I should have gone all in.

I mad a few doubtful moves as well.

Lots to study about that game anyway!

Colour code is:

Green - doubtful
Blue - bad
Red - very bad

Moves in BOLD: Very lucky rolls

[ParadigmShifter]

Here's an article with some doubling advice. Seems to be you should take if your chance to win is 25% or more (although it says redoubling is different but I couldn't find the article about that he mentioned, or if I did it was behind a paywall.

https://bkgm.com/articles/Simborg/Doubl ... adeSimple/

Gonna start the next game, I'm 1-6 down after 3 games, first to 11 wins.

We roll doubles twice to see who starts, this game plays if a double is rolled when deciding who goes first, stakes are autodoubled (i.e. cube starts on 2). It did not double again when we rolled a second double.

I'M NOT PLAYING THAT RULE THOUGH, it's never used in tournaments, I think that's mainly for money play not match play. So I'm ignoring that the cube is showing 2, it's actually on 1. So the match score recorded by the Speccy will be out of sync from now on, sorry! I'll cross it out and scribble in the correct score though when I do a screengrab at the end of this game.

I roll a 21 to start. My preferred move with 21 is to move 1 off the midpoint L-N and split the back men with the 1 (A-B). Pretty sure that's the recommended opening move for 21. You can also run with 3 from the back, or move one back man 2 and the other 1.



I'm not going to keep crossing out the doubling cube Just a reminder game is not doubled here.

... so I do my standard 21 move, CPU rolls 33, it likes rolling doubles lol, and makes the bar point. It could also have made 2 new points instead if it wanted, but bar point is good to have, especially now it forms a 3-prime.



I roll 21 again.



I could either repeat my last move, making 2 points, or I could make opponents 3 point, which means I can escape with a 6 and I also have what is known as an "anchor" i.e. point in the opponent's home board I can keep there and menace the CPUs ability to add to its prime when it comes down from the midpoint.

I prefer the anchor and opponent rolls a 52. It buries one of its checkers on its 1 point and splits the back men



I roll 64 and also make my bar point. Opponent rolls 41 and makes its 1 point.



I roll 61 so decision time. I could hit with Q-W-X or I could split my anchor



I don't think loading more men on R or S is a good plan, need to hit or run I think

[ParadigmShifter]

So I decided to hit, but CPU hits back with a 41, and this complicated thing happened



Looks like my plan now needs to be staying back, trying to form good blockers in my inner board preferably in meantime, and hit back when I have the chance. I'm behind on pipcount quite a lot now so staying back is good for my timing. If I get hit again I could try and make multiple anchors in opponents inner board which always makes bearing off and coming in much more difficult. All about timing for me now really.

I come off bar straight away with a 62, and move another man from midpoint to bar point as well.

CPU gets a 61 and adds another man to its midpoint



I roll 54 looks like I should hit and make the point where I hit on



So I do that and opponent comes back on immediately with 42



I roll 63 and hit again. This is a more action packed game than the others. I'm back in this now



But it's a bit of a volatile situation now, CPU might get back on and hit again

[ParadigmShifter]

Woohoo CPU dances with a 66, that's unlucky.



Decisions to be made now! I could hit and move on (Q-U-V), I could make my 8 point again with L-P-Q, I could bring more ammo into the zone with K-P.

I could also hit loose with Q-U* and then either split my anchor or do K-L

I decide to hit and move on which is the safe play although I don't really like having 3 men on my 3 point. I need to get a win under my belt though really and I think playing safe here is better overall.

CPU immediately brings both back on with 51



Gonna go and get some beer for the rest of the game... I may count pips when I get back to see how far ahead in the count I am, if at all Knowing whether you are ahead in the race or not is important in games like this really.


So pip counting (there are faster ways to count pips if you practice doing it, but I don't, and there's no time limit here of course)

Me: 2x22 + 14 + 2x13 + 2x7 + 5x6 + 3x3 = 137
CPU: 24 + 20 + 3x13 + 3x8 + 2x7 + 3x6 + 2x1 = 141

So I'm 4 pips ahead which is not much (I have the throw though which is worth about 8 on average).

So want to still take this steady not too many risks if I can.

I roll 62 and can break my anchor and make the K point (C-I-K) which is looking like a good idea I suppose



Although having an anchor is useful and last man back is looking ahead at the 3 prime, and it could also be hit and CPU make a point where it hits as well which would be worst thing that could happen.

I could also hit and make my 1 point with R-X* V-X which gives me 3 points in my inner board. That looks good too, especially if CPU dances.3rd man on V at the moment is kind of superfluous would be better making a point on 1 I think. Leaves 2 blots though, but if CPU dances I can consider a double (might be too good, dunno). Don't think so with 2 blots.

[ParadigmShifter]

Talked myself into hitting and making 3 points in my inner board, CPU rolls 23 and makes my golden point.

So I don't want to double I think



Anything could happen here then.

I roll 42, make my 7 point again, leaving 2 blots which is a bit worrying, CPU rolls 54 and hits one of them, sending me to bar. At least it has broken its anchor on my 5 point I suppose.



I come on with 33, can't do much else apart from come on and move checker on my midpoint the other three 3s.

CPU rolls 31 and makes a 4-prime and I have 3 men stuck behind it now. 62 would be nice now for me (although would leave a blot in my inner board, so 21 or 11 is better).



Instead I roll 64, that's really bad lol



Even though it's terrible I think I need to run with the 6 from the back, it's bad because it can't then move the other 4.

Other choice looks to be R-W, S-W which leaves a blot that can be hit as well but I get another point in my inner table. But if I don't see a 6 for a while I'm gonna crunch again.

So I take my bad medicine. CPU rolls 54 and makes its K point. It could have hit me there but would be 6 away from my anchor so that's a bit risky I suppose.



A 66 right now would be great for me lol

I get another 64 that's ok, think I need to escape really, CPU gets 42 and adds another to the bar point.



I get 43 and make another point in my inner board, CPU gets a 53 and leaves a blot. Could be my big chance now

[ParadigmShifter]

I roll 33 so gonna have to count pips again. I can't hit and I can't move my back man, so need to decide if just running is best plan or if I need to hit at least one more time I think. That's assuming I manage to get past CPU blockers of course later on lol



So pipcount is:

ME: 2x1 + 3x2 + 2x3 + 2x4 + 2x6 + 7 + 2x16 + 22 = 95
CPU: 2x1 + 3x5 + 2x6 + 3x7 + 2x8 + 2x11 + 13 = 101

But I've just rolled 12 pips, so it will be 83 to 101 (18 ahead) after this move (regardless of what I do). I think I should try and run then I guess? And hope(!) I can get my back man out without any problems.

Or I could crunch my board a bit and wait a bit longer see if I can hit and slow down CPU a bit more... decisions.

Decide to wait 1 more turn see if I get a chance to hit, CPU then rolls a 66, oh dear.



So CPU is 6 ahead in the race (I trail 83 to 77), but it's my roll. If I roll a 6 I'm running! Again a 66 would be super in this position.

OK I roll a 64, that would put me up 73 to 77, so CPU has a slight edge in the race. I have to run though and take my chances, can't afford to get hit.

I run. CPU gets 32, good, keep rolling low please



Pips are now 73 - 72 but I have the roll. Maybe I want to double here to try and get back in the match?

Decide to wait since my back men have quite a way to come into my inner table, so CPU will start bearing off first. I roll 63, bring 1 man in, move a back marker 3. Pips are 64-72, CPU to roll. It gets 64



Pips are me: 64, CPU 62. CPU has a big stack on 5 though they are going to be hard to bear off. But, he will start bearing off first so be ahead in men off before I start bearing off. Probably wait a bit to double then. Knowing CPU luck it will get 55 or 66

I roll, get 41, pip count for me is 59. CPU rolls 33, bears 2 off, its on 60. I'm still ahead on pips but CPU has borne off 2. I still need to get my last 2 men in inner table as well.



Bit of a nailbiting finish.

I get 54, 50 pips left. I should probably have moved 1 man in so I could maybe bear a man off next throw.

CPU gets 11, another 4 off. It's on 60 pips



I get a 41, CPU gets another double, 33, takes 2 off the 6 point.



I need to start getting 2 a turn off and the CPU needs to stop rolling doubles.

Pips: Me 45 - 34 CPU. I miscounted the pips earlier I think, oops Good job I didn't double.

[ParadigmShifter]

I'll double check the pips and men off from now on

I got a 63, so 2 off. My pips: 36 (3 lots of 1234 = 3x10 + 6) CPU pips: 6x5 + 4 = 34. My men off: 2 CPU men off: 8

CPU doubles... hmm. Think I have to take it to try and get back in match, otherwise I am 7-1 down (doubling cube should not be showing 2, it's on 1 really cos of the silly rule it plays where a double rolled when deciding who to go first autodoubles).



I accept the double. CPU rolls a 53. It needed a 5, good job it did not get a double 5, all over for me in that case. It can only bear 1 man off.

Pip count Me: 36 - 26 CPU. Men off: Me 2 - 9 CPU

I roll 63, another 2 men off.

Pips: Me 27 - 26 CPU. Men off: Me 4 - 9 CPU



CPU rolls 61, only 1 off again. CPU pips: 20 men off: 10

I roll a 33 that's actually bad, only get 1 off

Looking like another loss here. Need doubles soon or CPU needs to start rolling 21s



CPU rolls 53, only 1 off again, but one off the 5, looking grim here. I roll 52 taking 2 off. It's not really about pipcount now it's about men off, and CPU is winning that game.



CPU rolls 51, takes off another 2. I need a double right now...

Well I get 1, double 1. I was hoping for better than that CPU needs to not bear off last 2 men and I need a double 2 or higher. Even if CPU rolls 21 twice it's off in 2.



CPU rolls 62 and wins



It only wins 2 points though cos of the silly autodouble thing.

Match score after 4 games:

Me 1 - 8 Psion Backgammon (level 4).

It's incorrectly reporting 10-1 on the title screen so I won't screengrab that

So that was close glad I didn't double when I thought I was farther ahead in pips though!

Definitely need to get my skates on next game lol

GG

[ParadigmShifter]

I still should have accepted the double even though I was likely to lose there since CPU being on 7 vs, CPU being on 8 (so needing either 4 or 3 points to win the match) does not make much of a difference really, since it would still win with a 4 pointer game (so cube on 4 or cube showing 2 and winning a gammon). So that was basically a "free take" for me since it's rare to only lose 1 point per game, usually it gets doubled.

I definitely need a win next game though.

Not gonna do the GNU analysis of the game tonight though. I'll make sure I get the pre-match score correct though this time so it properly takes that into account.

If the CPU gets 2 points next game then the Crawford rule applies (it's 1 point away from winning so no one would be able to double for the following one game (only)). So I'd better win the next game or else only lose 1 point I think lol

There's been no gammons yet either a nice gammon for me would be ideal. Gammons are quite common in Backgammon really.

I think I can only afford to lose 1 more game this match or else I am defeated

I might give it a rematch though it has played pretty well (it's been jammy of course in my opinion)

Might be worth me doubling early if I'm only just ahead to try and get more points if I do win next match.

There's no point CPU ever redoubling to over 4 on the cube now so if that occurs I will ignore that too (that would only give an unfair advantage to me). If it redoubles to 4x I can redouble to 8x of course. EDIT: And of course I should, immediately, since in matchplay it doesn't matter if you lose 12-1 or 16-1, it's still a loss. But a fluke win with cube on 8x to get me to 9-8 up would be fantastic.

Surely I am due some good luck soon!

[ParadigmShifter]

GNUs verdict on the last match is in




We both made 3 very bad moves (red).
I mad no bad moves though vs. CPUs 2 bad moves (blue).
1 doubtful move each.

Note: The player settings are set to the defaults in GNU, which is "World Class" (lol). So it is much more harsh as to what it considers bad moves with those settings I think.

EDIT: Here are the settings it is using for analysis



Which means it considers a very bad move to be one where your match equity (i.e. expected number of points won compared to win chance when making the best move) goes down by 0.12 points or more.

I should have doubled when CPU danced on the bar with 66. But we see how the game turned out so it's a good job I didn't lol
It thinks CPU should have doubled the turn before (still thinks I should have passed though).

I should not have taken the double at the end... but overall I played a bit better than the CPU.



CPU was looking at a 92.1% chance to win there. Like I said I felt it was a free take really though, since that puts CPU 3 away in the match which is pretty similar to being 4 away really I think. Also, we got to see a game played out to the end rather than see a resignation and a sense of "what if?"

Surely my luck has to change a bit in the next game.

[ParadigmShifter]

Match is back on, those are the corrected scores (should not have been autodoubled last game for rolling a double when seeing who goes first).

Game is first to 11 points so CPU is 3 away, I am 10(!) away. This is the 5th game about to start.

We get doubles again in the rolloff lol, so doubling cube is again incorrectly showing 2 when it should be undoubled.

CPU wins with a 61 and makes the standard opening, make the bar point. 61 is 2nd best opening roll after 31 (make golden point with that).



I roll 53 and make my 3 point.

CPU rolls 64 and runs from the back



I roll 51. L-Q is obvious with the 5. For the 1 I can either split my back men (can't escape though if I roll a 6) or if I want to slot my 5 point (S-T), hoping to make it next roll.



Or I could hit on X and split (or even slot my 5 point as well lol, leaves 2 blots way too risky I think)

I decide the safer play (split back men) is better so I do that. CPU rolls 21 not very good. Then I roll a double 2, pretty good, probably make 2 more points I think.



So I make my 2 points, midpoint is looking light now with only 2 on it. CPU gets a 65 and escapes with its back man. Looking like this is going to be a race although I am more likely to be hit I think, which is bad.



I roll a 52 probably need to get my back men moving I think then. Or I could clear my midpoint since I am unlikely to hit from there in this position, and work on building my blockers for when/if I hit CPU as it is coming round.

[ParadigmShifter]

I run and am immediately hit with a 54.

Then I get 33



I make 4 points in my inner board with my 33. CPU gets 51 and does some tidying up. I then roll 43, probably want to clear my midpoint now I think and work on my defences, or I could advance with one of my back men instead. I need to hit though so staying back is probably best option?



I decide not to clear my midpoint yet instead do another building move, still staying back with my back men. CPU rolls a 21 and piles them up on his 6 point. I roll 56



Might have to count pips now to see if running is my best option here or if I want to make 5 points in my inner board with my 56.

Pip count:

Me: 24 + 22 + 2x13 + 8 + 7 + 2x6 + 3x5 + 2x4 + 2x3 = 128, and I just rolled a 65 so will be on 117 after I take my move.
CPU: 3x13 + 2x8 + 3x7 + 7x6 = 118

So I'll only be 1 ahead after I take my move - staying back is best then.

So make my 2 point, CPU rolls 32 and is safe.



I get a 52, probably want to make an anchor but then I will have to split the men on my midpoint leaving a blot which can be hit with a 1

Pips: Will be Me 117 - 7 = 110, CPU 113 after I make this move.

Do that, luckily CPU does not roll a 1, it gets a 62.



Pips: Me 110 - 105 CPU. So a 66 for me would be nice or a 62 which would hit. But scores are still close, could do a risky cube here since I'm miles behind in the match, decide against it and roll.

I roll 64. So I can run with 1 from the back but I'm very likely to be hit, depends if it can also be safe after the hit.

Have to do some quick maths. Pips will be: Me 100 - 105 CPU after I take this move

[ParadigmShifter]

So this is how I work out odds.


11 12 13 14 15 16
21 22 23 24 25 26
31 32 33 34 35 36
41 42 43 44 45 46
51 52 53 54 55 56
61 62 63 64 65 66

Are all possible rolls (36).

If I run I will 3, 4 and 5 away from being hit so that's all of these in italics

11 12 13 14 15 16
21 22 23 24 25 26
31 32 33 34 35 36
41 42 43 44 45 46
51 52 53 54 55 56
61 62 63 64 65 66

So that's 24/36 chance to get hit with 1 die roll. I also get hit with an 8 on 2 dice so that would be 62, 26, 22 so 3 more possibilities = 27/36.

Not all of those leave the CPU safe though. CPU is safe with 34, 43, 35, 53, 45, 54, 22. So chance for me to be hit is 27/36. Chance for me to be hit and the CPU to be safe afterwards is 6/36 which is 1 in 6. Hit and CPU being safe is what I want to avoid.

1/6 = 16.67% chance for CPU to hit and be safe
27/36 = 75% chance to be hit and CPU to not be safe.

Not liking those odds really I think I should keep my anchor for at least 1 more roll.

I'm also hit and CPU is safe with 44 so slightly more than 1/6 chance for that (7/36 = 19.44%).

So stay back still, slotting my final inner board point. CPU rolls 52 and buries a checker on 1



I get a 63 anyway. My timing to run is better now because of the CPU blot on A. It can only hit me and be safe with 23, 32, 24, 42 I think.

CPU misses with 52, makes a blot 6 away from mine.



I'm very likely to be hit and CPU to be safe if I don't escape this turn. Even if I hit it could hit coming back on with a 1, unless I roll 66 (which would probably be game winning for me). Critical moment here. Maybe I should risk a double here, that could go wrong quickly if I don't escape or hit.

I hit with any 6 (11/36), 15, 51, 24, 42 so 15/36 = 41.67%. I escape without hitting with 16, 61. So chance of hitting or escaping which puts me in a good spot is 17/36 = 47.22%.

To cube or not to cube, that is the question. If CPU hits and becomes safe it's probably an immediate redouble though lol.

EDIT: I also escape without hitting with 25, 52 so that's 19/36 chance for a good result for me. So might chance a cube here...

[ParadigmShifter]

Knackers I double, it's accepted and roll a 41. Cube should be showing 2 here. More maths is needed to see if I am better off moving up 1 or staying where I am (usually advancing is best but could depend on if CPU rolls a double or not though).



Best count pips as well:

Me: 22 + 13 + 8 + 7 + 2x6 + 2x5 + 2x4 + 2x3 + 2x2 + 1 = 91, with 5 to take so 86.
CPU: 9 + 2x8 + 4x7 + 6x6 + 2x1 = 91

So pretty even, but I am stuck and likely to be hit next roll. I still think it was worth a double because if I had hit I could have lost my chance to double the game stakes, and I need to start scoring points (assuming I win of course lol, which is looking less likely now).

Now I need to work out whether to advance or stay back.

I stopped working out the odds when I saw CPU could hit with any roll if I stayed where I was lol Not that CPU would have hit 100%. So I advance 1, CPU rolls 63 and does not hit (couldn't make himself safe) so finally some good luck there.

Then I roll 64 so can escape. Definitely not staying back here lol regardless of pipcount, it's too risky.



So got away with that risky double there I'd probably have doubled after this roll (depending on count) anyway, but I thought if I would hit it may be too late to double (could have won a gammon for same result though I suppose).

I work out the pips anyway

Me 86 - 82 CPU with me to move 10 now so it will be 76 - 82 in my favour. My men are much better for bearing off this game though (I have all spaces covered in my inner board so guaranteed 2 a turn off for a while when I get going)

I make my move, CPU then rolls 65



And I roll 51.

Pips after I move: Me 70 - 71 CPU

So move 2 in with the 51, CPU rolls 41



Pips after that Me 70 - 65 CPU

But i just rolled a 64 so will be 60 - 65 to me, and my bearing off position looks a lot stronger. CPU could still roll big doubles though!

[ParadigmShifter]

Exciting stuff then.

Postimage webserver is down now though looks like so may have to adjourn

It's been a tense game this one.

... and Postimage is back up, game resumes. Nearly finished this game.



CPU rolls 41 and is ready to start bearing off, so am I. Not going to count pips any more it's all about men off unless I get redoubled again.

I've just rolled a 11 there so not very good, I will take 2 off my 2 point.

And the CPU, King of Jammy Rolls, gets a 66 and takes 4 off. No point drawing arrows when it's obvious what happened. CPU 4 - 2 Me in men off stakes.

I roll 42 so I will have 4 off after that. 4-4 in men off. CPU has the advantage now it might redouble after my go I may as well accept if it does I think?



Yup, CPU redoubles. If I accept and lose the game I lose the match. If I resign here it is 10-1 up and it will be a Crawford game (no doubling allowed) for 1 game after this.

I think I should accept and go down in a blaze of glory lol

5s and 4s are bad for the CPU here though.



I accept the double and CPU continues with the luck and takes another 4 off with 33.

I roll 65 though which is ok.



I should probably have redoubled to 8 anyway, doesn't matter if I lose 12-1 or 16-1.

CPU gets 65 and only gets 1 off. I then redouble to 8 lol

CPU obviously accepts. If it redoubles again I will ignore it cos CPU only needs to win to win the match, so there's no point it doubling now. Cube should be showing 8 cos of the autodouble at start etc. etc.

CPU has 6 to bear off I have 7, so if I get a 66 soon I might still win It's a small hope. I got a 53.

.

CPU rolls 43 and only gets 1 off again. But then I roll 42 so can only take 1 off also, from the 6



CPU redoubled in the meantime which I accept and ignore since it would not double if it knew it doesn't need to to win the match.

CPU rolls 62 and is down to 3 on its 1 point. It's off in 2 whatever it rolls. If it rolls any double it will win next roll. I roll 61. So I need 66 to win, otherwise I lose the match.



CPU rolls 43 and is down to 1 man on its 1 point. I still need 66 to win.



I don't roll a 66 of course (rolled 51) and lose the match 16-1.

[ParadigmShifter]

So the answer to the question in the OP is *drumroll*

No, I can't beat Psion Backgammon on the hardest level.

It tonked me 16-1.

I shouldn't have accepted the double at the end of course but didn't fancy being 10-1 down needing to win all games from then on, and the next game was the Crawford game so it would be only worth 1 point (or 2 for a gammon, 3 for a backgammon).

It was jammy getting a double 6 nearly as soon as it started bearing off of course. And then a 33! When it had loads on its 3 point.

Might have a rematch at some point because I know I can beat it in a match to 11, have done so before.

Won't be a rematch soon though lol

NOTE: I don't think the dice are rigged in its favour, that's just how backgammon goes sometimes. Important thing is not to get tilted when your opponent is lucky.

There's a match I played ages ago on WoS where I won (no screenshots that time though) I will find out what the score was.

EDIT: Wow, I played 28 games against it last time (was no fixed match score looks like). And I think I let the extra doubling for ties at the rolloff stand? (Thinking about it, I remember not letting the extra doubles stand, I kept my own score in this match like I did in the match just played)

Here was my after match report from WoS

Match scores, 28 games in total played. Looks like I decided to play to 25...

Game 1: Race game, I doubled early and brought it home 2-0 to me
Game 2: It made some questionable plays not hitting me on my home side when it could have. Won a lucky backgammon (triple game) 5-0 to me
Game 3: Doubled after an early 66, CPU hit me when I was bearing off. Held on for the win 7-0
Game 4: Close game, I double and it is taken. I win in the end 9-0
Game 5: To and fro early after a CPU 66 early on. I sneak ahead and double it. Both ended up with primes in inner board and he got me first and doubled, which I took since I still had my prime. CPU won with the doubling cube showing 4x. 9-4
Game 6: Uneventful. I offer a double when a bit too strong, CPU declines. 10-4 to me
Game 7: CPU hits my first move runner (was a 64 I rolled I think) then I dance on the bar. Turns into a blitz (both sides hitting each other game). CPU doubles and I accept. I make a good recovery and win: 12-4 to me
Game 8: CPU in good position and doubles, full of confidence I take in a bit of a risky situation. In the end I had 1 roll at double 6 to win, got 65, lost. 12-6
Game 9: Lots of counter hits, CPU went ahead but then I hit several times and was ahead again. I doubled -> CPU declined. 13-6
Game 10: CPU rolled double after double. When it doubled me I declined. 13-7
Game 11: I was in too strong a position to double (was looking like a gammon) so didn't, in the end CPU got lucky and only lost a single game. 14-7
Game 12: CPU got 66 first roll it had then went on to make a lot of hits. When it doubled I declined. 14-8
Game 13: Similar to last game, CPU big lead, when it doubled I declined. 14-9
Game 14: I get the upper hand and double, CPU declines. 15-9
Game 15: CPU leaves a lot of hittable targets so I double -> taken. I hit 2 of his but when he returns hits one of my runners. Interesting game. I get well ahead but then when about to start bearing off he has a lucky hit and also has a 5-prime in his inner table. I can't get back on quick enough, CPU doubles, I drop with the doubling cube on 2x. 15-11
Game16: I was in a good position and double -> taken. Then it has a hot streak and wins the game. 15-13
Game 17: CPU keeps rolling doubles again. I drop when it doubles. 15-14
Game 18: Another race, CPU rolls lots of doubles again and doubles -> I drop. 15-15 even stevens
Game 19: CPU leaves a lot of men unsafe and I hit, then refuses to make my 5-point when it could have, so I double -> taken. Lots of questionable moves then from CPU, like refusing to hit my advanced runners on my side of board. It sneaks a gammon save 17-15
Game 20: Failed to hit CPU on its own 1-point, then get hit back immediately. CPU then gets in a good position and doubles, I drop 17-16
Game 21: I was a long way behind again so decline a double. 17-17 now
Game 22: Straight race, I won, 18-17 to me
Game 23: Try and play a back game, took a double I shouldn't have, got gammoned. Speccy takes the lead 21-18
Game 24: I get ahead early and double, CPU declines. 21-19 behind now
Game 25: I go ahead in the game and double -> taken. CPU hits me just as I was about to start bearing off and wins a gammon because of it CPU leads 23-19
Game 26: CPU well ahead, offers a double which I decline. CPU leads 24-19, one away from winning.
Game 27 (Crawford): I play a bit of a back game which confuses it and win a gammon. 24-21 to CPU
Game 28: Aggressive back play from me again, it does not like that. I double and it takes and win a gammon, I win 27 to 24!!!

So I see CPU got to 24, one away from winning. I double gamed it in the Crawford game and the next game (where I could double).

So that was a very close match. Unlike this one lol

I played all the Backgammon games on the speccy to test them out. Psion one was the only one which was any good and knew the rules properly. All the others are terrible for one reason or another and I hardly played any games against them.

EDIT:
Game 28: Aggressive back play from me again, it does not like that. I double and it takes and win a gammon, I win 27 to 24!!!

That suggests I won a backgammon there (triple game), otherwise I would not have scored 6? Even if I won a gammon with cube on 2 I would have still won 25-24, so dunno what went on with my after match report there lol Was probably well after beer o'clock when I typed up my report.

EDIT: No I backgammoned it, I did take a screenshot of that lol



I'm off even with a 21 and it has no pieces off and one in my inner table = backgammoned for a triple game with cube showing 2 for 6 points total.

I remember making notes about how each game went though lol so I could do that good summary of the games. They sounded more exciting than these ones which were just frustrating for me!

No idea why I decided to play up to 25, I don't even think the final of the Backgammon World Championship in Monte Carlo they play that many (I think it might be up to 17 games???).

EDIT: Looks like I was wrong about that!

The World Championship of Backgammon is held each year at the Loew's Hotel in Monte Carlo. Typically 200 to 250 people participate in the Championship section. Matches begin at 17 points in the early rounds and increase to 25 points in the finals.

I think I had been watching the World Champs in Monte Carlo (on Youtube) when I played the match then EDIT: Looks like they only played to 21 last year though???

Spoiler alert: I'm not going to try going to Monte Carlo to qualify/play in the World Championship if I can't consistently beat Psion Backgammon of course

[ParadigmShifter]

I'm surprised at how well it plays considering it's a 16K game!

Things they should have improved about it if they did a 48K version or a sequel:

Make it so you can set the match score, then it will know when to stop doubling.

Make the silly auto-redouble when you roll doubles to decide who goes first optional (default should be OFF).

From my report it sounds like it struggles badly against back games (games where opponent has more than 1 point in your inner table), so they probably would want to improve that part of the game.

Make it more aggressively hit and play a bit less safer than it does, unless it is ahead in the match.

Have an option to show pips (and if you can set match score, obviously show that as well).

Make it so it knows about the Crawford rule (again make it optional, default: ON) if you play a match rather than a one-off (money) game.

Once it knows about match score it should change its doubling/redoubling strategy - you want to double early if you need to catch up in match score. You always want to double post-Crawford if you are behind as early as possible (preferably when you know they will accept of course).

Some people like to play going the other way (so you move clockwise rather than anticlockwise), so allow an option to flip the board left to right. Of course in a real game one person plays clockwise and the other plays anticlockwise so you don't always get your preference (my preference is the default though, me going anticlockwise from top left to bottom right).

Have an option to change the colours on the board, my cyan pieces were pretty ugly to look at. The piece stacking graphics when you have more than 5 checkers on a point is ugly as well.

Speed up the dice rolling animation, at least as an option

Have a proper count of men borne off so you don't have to count them manually. There's a load of wasted space on right hand side they could have used for that obviously.

Have an option to number the points rather than use letters. Probably have to use select piece cursor and where to move it to as well then. Although mouse support would obviously be excellent too!

This is what gnu interface looks like, it also shows where you can move to:



It's still impressive for 1983/16K game. I've not played against any of the lower levels before, I went straight to level 4 (the hardest).

At least I hope some of the games I played were sufficiently entertaining Some of the games were exciting anyway! Even if we both played bad.

I should probably stick to Scrabble for a bit lol.

Maybe I should batter the Psion Scrabble to get revenge

[sn3j]

Nice read. It helped me to get into Backgammon, although it's difficult to follow the moves at times.
The 1-16 defeat seems a bit ungraceful though.

[ParadigmShifter]

Cheers. I had my chances in all the games but couldn't hold on for a win in any of them.

Game before the last one I shouldn't have doubled (first time) when I did I was too good to double! So CPU should have dropped! But I still went on to lose that game lol

CPU rolling a lot of doubles when bearing off was a bit annoying though!

As I said I don't think it fiddles the rolls or anything, and in that long match I had in 2023 I was way ahead until it came back to 24 - 21 (one away), and then I won two games to pip it at the post. I also rolled "joker" (i.e. extremely lucky roll) in one game (in the match I just played) when I rolled that 55, so luck evens out in the end. In the long run best player should win.

It's a great game backgammon mad things like that can and do happen though, which makes games more exciting than most traditional board games where usually you know who is going to win after a while. I still could have won that last game (which I had doubled to 8 - it was right to double to 8 since I still would have lost if cube was on 4, so it was no risk double) if I'd got a 66 at the end there!

I hope I didn't come across as ungracious anyway I know how silly games of backgammon can get.

I'd recommend playing the Psion version if you want to try a game of backgammon.

Unless anyone wants to take me on on backgammon247? You don't need to register or anything (it's just a web page, no need to join up). but you do need a code for a matchup, which expires after a while (think it is 30 mins? May be 10 mins, can't remember) so if anyone would like a game let me know and I will create a match.

That site is here:

https://www.247backgammon.org/

Computer is not very good on that site though, I usually give it a good beating (although I said that about Psion backgammon too lol).

Some sites let you play without the doubling cube in play if you want but that reduces the skill/fun considerably IMO. You can't play without the cube in Psion. (Shame about the autodouble rule though, as I said, no one plays that rule).

[sn3j]

Yeah my impression was CPU had a lot of lucky rolls. Maybe there's a secret to level 4? A liitle bit of disassembly could reveal this.
I'm just busy atm and will stuff my sparetime into coding methinks, but will be following the thread if you're going to do a rematch.