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

General software. From trouble with the Banyan Tree to OCP Art Studio, post any general software chat here. Could include game challenges...
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ParadigmShifter
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Re: Let's see if I can beat Psion Backgammon on highest level then

Post by ParadigmShifter »

Reading back the report of my 28 game match to 25, it seems the CPU struggles badly if you play a back game (i.e. keep back with 4+ checkers in their inner board, make anchors, etc.). But I needed to be hit more than I was for that, never had more than 3 checkers in opponents inner board, which was why in one of the games I was actively trying to get hit when I was a long way behind, although my timing for that was way off (ended up crunching instead).

It just seems to play a very safe blocking game, which is fine but not always the best plan against good players. At least it doesn't make the classic noob mistake of playing ONLY the safest move which is bad, you end up with very few points to block with then, and lots of checkers on only a few points (known as "candlesticks", for obvious reasons). You want make connected blocks of points (a prime) which it does quite well (so did I but I did not get chances to hit back when I had good blockers, I was usually stuck behind decent blockers from CPU).

I should have started counting pips earlier than I did - it's not worth running if you are a fair way behind in the pipcount, it's better to stay back, work on your blockers, wait for a hit. I think I ran too early before I started taking the CPU opponent seriously enough :)

EDIT: My timing was good in the last game though I thought I only ran when I had a decent chance (after it left a blot in its inner board), unfortunately I wasn't able to escape or hit the move after - although it was lucky I didn't get hit and CPU could make itself safe there). Then it ruined all my good planning with that 66 and 33 when it was bearing off, lol :) That's how it goes sometimes!

If you hang back you may need to get yourself hit to provide better tempo (i.e. don't crunch your board and waste all those blockers you spent time building). It's better to be hit and provide chances to hit later on when CPU is bearing off or about to than to crunch your board.

EDIT: Since it's a 16K game I expect the AI to be not too sophisticated. It might do a 2-ply evaluation of each position (i.e. each move it works out what will happen on all possibilities of next 2 rolls perhaps)? But that would probably use a lot of memory so maybe not? Maybe it just gives bonus points for making connected blockers/making more blockers etc. I expect it works out chance to be hit if it leaves blots though and plays the safest move which does leave blots. I don't know if it is then able to work out chance to become safe next move if it isn't hit etc.

Backgammon is quite hard to do AI for you can't do minimax, you have to do Monte Carlo (roll out a lot of positions and work out what happens on average) but that uses a lot of CPU time.
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ParadigmShifter
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Re: Let's see if I can beat Psion Backgammon on highest level then

Post by ParadigmShifter »

I think I will do a rematch at some point, since it was a shame there wasn't much variety in the type of games that we played there, they were all blocking/priming games.

Types of games we didn't really see:

Racing game, where you roll high early on (perhaps a 65 start then 66 or something) and just leg it. Those games are fast but not very skilful however.

Blitz game: That is where you load your half of the board (so lower half of board for me) with as many checkers as you can, don't really care about safety of them that much, you aim to constantly hit your opponents men and send them to the bar as often as possible, until your inevitable numbers of men in the zone makes enough points in your inner board to stop them coming on again. If the blitz player gets hit it just wants to run as fast as possible back into the zone ;) If the opponents back men manage to escape you are usually losing though. Every time you hit your opponent they have to waste 1 die roll coming back on, so they rarely have time to build decent blockers in their inner board to stop you from running back into the blitz zone.

Back game: where you are a long way behind but have multiple anchors in opponents inner board so that makes it awkward for them to bear off. You work on your own inner board position and if and when you hit you are in a good position again. Those games are very different style of play needed to win, they often go wrong though :)

Obviously you don't get to pick what kind of game you play really though, it depends on how the opening couple of rolls go. You want to be able to recognise what sort of game you are best off playing at any point and change your strategy accordingly. I should have started a blitzing strategy in one of the games according to GNU (the one where it did not like my risky slotting play - I should have hit and attempted a blitz game).
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Re: Let's see if I can beat Psion Backgammon on highest level then

Post by equinox »

There will be more interest if you do Sam Fox Strip Poker.
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ParadigmShifter
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Re: Let's see if I can beat Psion Backgammon on highest level then

Post by ParadigmShifter »

I'm not risking having to post myself in various states of undress though if I lose. You have to play these games properly as the developers intended.
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