In fantasy baseball, owners are always looking to take advantage of the lucky and unlucky players by selling high and buying low. I wanted an easy, yet comprehensive stat to find players under or over performing their season’s stats. The final results led me to Luck.
For fantasy purposes, the two hitter “luck” factors are BABIP and HR/FB rate. A few extra infield hits or nicely place pop ups that fall and a player’s stats can be inflated. I wanted to show how far a player’s stats deviate from where they should be. Right now, I am only looking at whole season numbers. I will look into per PA values later this week.
Using slyde12′s xBABIP formula, I subtract the players BABIP from their xBABIP. Then I multiply difference by the batted balls in play to get the number of extra non-home run hits the player gets in the season.
To get the projected number of home runs, I took their home runs minus the number of FB times their regressed HR/FB rate. Since home runs are more damaging then regular hits, I doubled the value of them. These numbers (1 for hits, 2 for HRs) line up with the general run values for these types of plays.
The two numbers are added together and then adjusted so the luckiest player has a value of around 10 and the unluckiest has a value of around -10.
Here are 2011′s luckiest and unlucky hitters:
Note: Right now the numbers are not park or league adjusted, but I hope add those factors soon.
The luckiest hitter for the season is Adrian Gonzalez. His BABIP (0.381) is about 50 points higher than his xBABIP (0.330). Also, he has a HR/FB% of 16.9%. This value is about twice the league average of 9% HR/FB.
With pitchers, I followed the same format as the hitters with the exception that I also added LOB%. I subtracted the league average BABIP (0.290) and HR/FB% (9%) from the player’s values. Additionally, I subtracted the pitcher’s LOB value from the league’s LOB%. Then, I multiplied the LOB% difference times the number of runners the pitcher allowed to get on base.
Again, I added up all the values, used a multiplier to set them to a -10 (unlucky) to +10 (luckiest) scale. Here is a list of the 2011 luckiest and unluckiest pitchers:
Jered Weaver comes in as the luckiest pitcher. It should not be that much of a surprise since he has a 0.257 BABIP, 5.4% HR/FB and a 80.7 LOB%. Each is significantly better than the league average.
I feel the basic framework is there to get a quick reference stat to find under and over valued players. Let me know what you think. Is there would be any other factors to be added? Is the -10 to +10 scale easy to follow? Thanks.