i'm trying to develop sport game and of course the biggest problem is ai. players have to cooperate in order to score. any ideas how to achive it? i'll try to enhance the subject problem later on.

There are lots of algorithms out there, but most will fall apart after a while as the player notices patterns. True team ai is very difficult to pull of in the laboratory environment, and nearly impossible in a game. Most of the ai you see in games is semi scripted, and semi rule based.

I'm no expert at any of this, but for ideas...

Have you considered designing set paterns for say an attack (for example football [soccer for americans out there...]) there could be a few laid out patterns for an offensive.

You could design a few set patterns for an offensive to start such as one player running with the ball another could be running ahead to the right, the ball could be passed to player 2, the ball could be crossed back, and the first player could move in to score.

There could be many of these patterns designed for an offensive play. Then, depending on experience in ai, you could modify these attacks regarding how the player tries to block the attack.

My apologies if you were after code that could do this, however i'm just a student of AI at the moment.
All the best with your idea! Sounds a like a cool project.

Ah, the guy above suggested it....
That'd be my mistake...

patterns aren't as bad as it would seem, but it might become boring after some time.

here's what i'm thinkin' of:
one player has the ball and there's few choices he can make: pass, shot, driblle (maybe more if something comes into my mind ;)) and he makes the decision depending on his parameters (eg. teamwork, self-confidence, passing, shooting, dribling etc). from this point of view, programming offence is not as hard as defence.

there are many players without the ball and they have to move into positions that 1) can give advantage to their team or 2) have to go back to retake the ball oponents have.
both these goals are similar difficult. probalbly there's only one place easiest to score - in very front of a goal. and if it is so, then all players will want to go there(!). and for sure - there's only one ball and if all players were to still the ball from the oposition, then only one player would be marked.
one answer i can think of is setting a position for each player, ie winger would always go to the wing etc. that's deffinitely not what i want achieve - it would be too easy to see for human player. and that implies only man-marking can be deployed.
zonal marking is little bit more complicated. maybe it would be good just to check for the distance between player and the ball and only the closest would try to take it?

thanx for answers guys you make me think abt it much more :)