Both Derek Carty and I have discussed the statistic BABIP in our columns here. Batting Average of Balls In Play measures the proportion of non-home run hits relative to all plate appearances excluding home runs, walks, sacrifices and strikeouts. We generally expect a player with an extremely low BABIP to improve as the season progresses and the adverse can be said for those with ridiculously high counts. There are exceptions, though, in situations when extremely slow or fast players hit a high percentage of their balls on the ground. For instance, if both BJ Upton and Pat Burrell hit 50 % of their balls on the ground, Upton is going to have a higher BABIP; he is faster and will leg out many more hits.

Dave Studeman, writer for The Hardbal Times, discovered a few years ago that the expected BABIP could be found by taking the line drive percentage of a batter and adding .120. If BJ Upton hits 20.5% line drives then we would expect his BABIP to be around the .325 mark. Any lower than that would indicate he has been unlucky and any higher than that would suggest luck. This is a tremendous tool when it comes to fantasy baseball because you can buy low/sell high based on what is expected to happen.

A player wants to hit as high a percentage of line drives as he can, so here are the top five line drive hitters with lower than expected BABIPs:

1. Edgar Renteria: 31.9% LD, .347 BABIP, .439 xBABIP
2. Todd Helton: 27.8% LD, .305 BABIP, .398 xBABIP
3. Nick Johnson: 26.9% LD, .226 BABIP, .389 xBABIP
4. Adrian Beltre: 26.7 % LD, .309 BABIP, .387 xBABIP
5. Stephen Drew: 25.3% LD, .268 BABIP, .373 xBABIP

Anybody thinking about trading or unloading Nick Johnson should hold onto him because he has been very unlucky this year. This will not keep up. Nobody is going to hit that many line drives on a consistent basis and have most of them caught. Here is the adverse side, the players with higher than expected BABIPs:

1. Kosuke Fukudome: 21.7% LD, .413 BABIP, .337 xBABIP
2. Jeremy Hermida: 19.1% LD, .394 BABIP, .311 xBABIP
3. Josh Willingham: 18.7% LD, .368 BABIP, .307 xBABIP
4. Yunel Escobar: 17.4%LD, .353 BABIP, .294 xBABIP
5. Torii Hunter: 17.9% LD, .348 BABIP, .299 xBABIP

Now, I am not necessarily advocating the buying/selling of these specific players but rather introducing an extremely helpful tool in determining when to trade someone. Though it does occasionally happen that a player can exceed expectations over the course of a season, if you are one to play by the odds then I would highly suggest going to Fangraphs and comparing the LD% to the BABIP. When someone comes forth with a trade this is a very interesting way to determine how to evaluate the proposal.