("Player" = human player controlling the action. "player" = soccer player in the field)
This was the first thing I tweeted about Super Sec Soccer:
Back then the AI players just ran towards the ball all the time which often led to 75% of the playing field being empty. And that's not ideal.
First, let me explain the goal I had in mind for the AI. It's not there to win the game, of even pass the ball to you so you can score. The idea is that the Player does all the important actions (apart from being the keeper). So that means that the AI players on your team "just" need to be at the right place - or at least, what could be the right place - so that the Player can switch to that player and perform an offensive or defensive action.
That means that they shouldn't all just run towards to ball all of the time. You might need them to be on the other side of the field so you can pass a ball at them. Or to run further back to play defense.
How this is done is that each player is either an attacker or a defender on the left or right side of the field. So each player has his own quadrant that he's responsible for. If the ball is in their area they just go right towards it. But if it's somewhere else on the field that might mean that they go in the opposite direction in anticipation of the chance that the ball might end up on that side of the field.
This is the AI in action with the lines displaying where they want to go:
This means the players are usually better spread out across the field. I say usually because I didn't want to completely remove the clumping 'cause sometimes, it's kind of fun :)
Here's a large chunk of a match, sped up 500%, where you can see the AI using the whole field:
In that GIF the blue team is completely controlled by the AI, including the blue selected player. That AI has a few more choices to make than just trying to be in the right location, but that's a post for an other time.