If the competition gets really cut-throat, or if your kid's team is losing badly (e.g. 0 and 10,) or if your team manager is just getting desperate, here are two strategies that will help you win some games. Although they are perfectly legal, strategies like these should generally be avoided. They detract from the purpose of the game, which is to just let the kids go out and have fun and learn some good character traits. These strategies don't really do that, but here they are:

It turns out that many younger players tend to hit very consistently. Player #9 may hit mostly fly balls to left field; player #5 may hit mostly grounders to second base, etc. A very motivated manager (with lots of spare time) will watch two or three of an opposing team's games, and take notes of where each player is likely to hit. When playing against that team, he will position his fielders accordingly. This does not work with older kids, and certainly not in the major leagues.

If your league has a player participation rule, some managers may conveniently "forget" about it, and leave their weaker players sitting on the bench for two or more consecutive innings (or for the whole game.) If you see this happening, assign two or more parents to independently keep track of which opposing players play in each inning. Notify the umpire if the rule has been clearly violated. This makes sure that every player gets to play, but it will result in forfeited games and long-term hard feelings. See "Winning and losing" below.