Batting Average On Balls In Play (BABIP): a statistic measuring the percentage of plate appearances ending with a batted ball in play (excluding home runs) for which the batter is credited with a hit. We use this statistic to try and determine how much luck has gone into a player's batting average. If a player has a high BABIP (well over .300), you can say that the player has been fortunate and chances are that more of the balls he puts in play are going to start turning into outs, and his batting average will dip. The opposite is also true. It's certainly not a sure thing, but it's a pretty good way to gauge luck and predict batting average change.
Line Drive Percentage (LD%): the percent of batted balls that are line drives. Pretty self-explanatory. Basically this shows you how often a player is squaring up the ball and hitting it well. A line drive will go for a hit about 75% of the time.
Ground Ball Percentage (GB%): the percent of batted balls that are ground balls.
Fly Ball Percentage (FB%): the percent of batted balls that are fly balls.
Strikeout Percentage (K%): the percent of a player's at-bats that result in a strikeout.
Isolated Power (ISO): measures the “true power” of a batter. The formula is Slugging Percentage minus Batting Average. This stat helps up see how much power a batter is hitting for without just looking strictly at home runs.
Win Probability Added (WPA): a system in which each player is given credit toward helping his team win, based on play-by-play data and the impact each specific play has on the team's probability of winning. This one is a lot of fun. It tries to pinpoint exactly how much each individual player has added to his team's chance of winning. If that's not enough explanation for you, you can read more about it here.
Clutch: measures how a player performs in high leverage situations. Every situation a batter faces is a certain level of "leverage", meaning importance in terms of winning the game. If a player comes up with "big hits" and contributes in high-importance situation, his clutch number will be high, and vice versa.
Now that we have the statistics defined, let's take a look at the numbers for your 2011 Pittsburgh Pirates.
- Andrew McCutchen has been the Pirates best player by far and has the highest WPA of the bunch. That's not much of a surprise. Keep in mind this is an offense-only study; if you throw in the defensive numbers, McCutchen's lead would be much greater.
- A surprising second place on the WPA scale is Garrett Jones. He is hitting just .251/.342/.338 with 8 homers, but has come up with some big hits (he has the team's highest CLUTCH rating) and has helped this team win some ball games.
- The trio of catchers is basically atop the list in LD%. Unfortunately, Ryan Doumit and Chris Snyder are on the DL (Snyder probably won't be returning), and Michael McKenry has a very small sample of at-bats, so we can't take anything from that number for him. Xavier Paul has squared the ball up quite a bit with a nice LD% of 26.3, and Ronny Cedeno, Neil Walker, and McCutchen all have pretty good numbers there as well.
- Strikeouts have been a big problem for the Pirates this year. Pedro Alvarez, Paul, Jones and Snyder all have big strikeout problems, and McCutchen, Walker, and Lyle Overbay certainly don't have encouraging numbers there either.
- The power is also very discouraging. McCutchen, Doumit, and Jones are the only ones with respectable numbers there. Alvarez's .096 is probably the most sickening number in that table.
- Jose Tabata has been bad at the plate. His -1.08 WPA is one of the worst on the team and he's hitting for basically no power. He can't keep the ball off the ground, which isn't a terrible thing with the good speed he has, but it hasn't worked out for him thus far as he is hitting for an ugly .265 batting average when we expected him to be flirting with .300 this year.