from my experience in thereal world, a 1-3-1 defense focus is to lock down on perimeter players especially but when the ball is move to the side ( example to the right ) the 1-3-1 formation the later 1 takes on the pf or c or whoever big man is on that side ( right ) of that with the ball .then the 3 ( positioned at right - center - left ) then that left player adjust by sliding down to guard the other big men, basically the person at the center doesnt move that much.same as it goes if the ball is move to the left. basically you may see that the side that doesnt have the ball that wingman is free but if he cuts the center ( not your center but whoever is place at the center of the 1-3-1) will take him but the point is they will make a long pass to him since the first 1( 1-3-1 ) picks up that guy the nearest player to him, this is where steals usually happens since the defensive playeron the side without the ball slides down when that long pass happens that is anticpated and more probably end up in steals.that is why i ask the bb or whoever had an idea what player is stationed at that later 1 because you have to have a lot of things to consider such as stamina ( he will keep on switching left to right as long as the ball is moving ) also if your looking at your opponents lineup if he has superior big men your better off doing 3-2. try to scout on their big men, even if he has 30k salary but isnt much of a factor ofensively probably its more of a defensive man but warning you might see him become a scoring option suddenly but i think its worth the gameble for him to score 20 points than see 3 of this outside players score 15 each or 20 each hope it helps