A common occurrence in 2012: Michael Bourn preventing an extra-base-hit.
So far in 2012, the Braves' pitching staff has allowed a Batting Average on Balls In Play (BABIP) of .324, which is third-highest in MLB behind only the Rockies (who play in the BABIP-friendly Coors Field) and Brewers. The Braves' mark is also much higher than the MLB average of .289. In the post, I'll look at the Braves' BABIP allowed for balls hit on the infield and for balls hit to the outfield.
If you aren't familiar with BABIP, it is batting average only on the plays that require fielders; home runs and strikeouts are not included. The version I use (from Baseball-Reference) also does not include sacrifice bunts, which I think is fair, since sac-bunters aren't actually trying to get a hit.
With pitchers, BABIP is often used as a sort of proxy for luck, with a high BABIP generally indicating that the pitcher has suffered poor luck, and vice-versa. However, defense obviously plays a huge role in BABIP, particularly on a team level, where the sample sizes are much larger. Other factors, such as defensive positioning and park factors, can have a large effect on BABIP as well. Keeping all of that in mind, let's look at the Braves' infield and outfield BABIP splits.
First up, here is how the Braves have done on balls hit to the infield ("to the infield" = balls that hit the ground in the infield or are first touched by an infielder). I used B-Ref's Event Finder to find that Braves pitchers have allowed 474 balls hit to the infield. Below is a comparison between the Braves' numbers and the MLB averages per 474 infield balls in play (IFBIP).
Let's take this column-by-column. "IFH" stands for infield hits; the Braves have allowed only slightly more of these than league average. "IFOF1B" represents singles that bounced in the infield but were fielded by outfielders; this is the most troubling aspect, as the Braves have allowed a whopping 43% more such hits than the league average. This indicates either horrendous luck, poor positioning, or terrible defensive range (or some combination of these). They've also allowed two more extra-base hits ("IFOFXBH") than the league average on balls that bounce in the infield, indicating poor luck or defense on balls bounced near the foul lines.
All of that adds up to a batting average on balls hit to the infield ("BABIF") that is a whopping 66 points higher than the league average and a slugging percentage on balls hit to the infield ("SLGBIF") 70 points higher. That's huge, and it has led to the Braves' Win Probability Added ("WPA") in these situations being half of the MLB average. What that means is that most teams have gained about 5 wins on balls hit to the infield, but the Braves have only gained a bit more than 2.
In other categories, the Braves are doing just fine; they've turned 1 more double play than average and allowed 3 fewer runners to reach on errors. Unfortunately, being a bit above average in those areas doesn't come close to outweighing all those extra hits. Taking everything in the above table into account, the Braves turn each ball hit on the infield into about 0.78 of an out; by contrast, the MLB average is 0.83 of an out per ball on the infield.
The outfield comparison is after the jump. The Braves do quite a bit better in that area.
The Braves have allowed 318 balls hit to the outfield ("OFBIP," i.e., balls that go beyond the infield on the fly). Here's how the Braves compare to the MLB average per 318 OFBIP:
The "OF1B" column represents singles that reached the outfield on the fly. The Braves have allowed about 10% more of these than average, but this could be partly due to poor defense by the infielders on line drives & pop-ups. (A fair number of line drive hits are hit low enough to be caught by a well-positioned or agile infielder.)
The Braves really shine in preventing extra-base hits to the outfield, however. They've allowed about 10% fewer outfield doubles than average, which is pretty good. Even better, they have yet to allow a triple--the only team in MLB that can make that claim.
Put all that together and you get a batting average on balls hit to the outfield ("BABOF") a bit better than league average and a slugging percentage on balls to the outfield ("SLGOF") that is 69 points better than average. The latter figure is highly impressive, though some of it may be due to good luck. However, given the defensive pedigree of the Braves' outfielders, I think it's fair to say that a lot of this extra-base-hit-prevention is due to the outfielders' great defensive range. When Martin Prado, Michael Bourn, and Jason Heyward take the field, the Braves cover more ground than just about any other outfield.
In terms of WPA, the Braves have lost just under 2 wins to balls hit to the outfield, which is about half of the league average. That's about a 1.5-win advantage for the Braves in these situations compared to the rest of the league.
Per ball hit to the outfield, the Braves get 0.60 of an out while giving up 0.53 total bases. The MLB averages are 0.59 outs and 0.59 total bases. Counting only extra bases (1 for a double, 2 for a triple, 3 for an inside-the-park homer), the Braves allow 0.12 per OFBIP, while the league average is 0.17; that means the Braves allow 29% fewer extra bases on balls hit to the OF.
I will be very interested to see if these trends continue throughout the season. I expect some regression (which would help the Braves' infield numbers but hurt their outfield numbers) but I also believe that there is something sustainable in these trends, given what we know about the great range in the Braves' outfield, and the lack thereof in the Braves' infield.
What do you guys think?