[quote]DBCooper wrote:
Hey raj, since you’re the big sabermetrician on here, what do you think of Batting on Balls In Play (BABIP)? [/quote]
I especially find useful in evaluating pitchers, and think it’s less effective when looking at hitters.
[quote]DBCooper wrote:
Personally, I don’t like it that much in this respect: I always hear people cite a low BABIP (I think the league average is about .330) as opposed to either that player’s career avg or the league avg as indication that the player is destined to start hitting better if his overall avg is low at the time.
For instance, say a player with a career avg of .280 is currently only hitting .245 and his BABIP is .275, down from his career mark of .330. Doesn’t that low BABIP this year indicate that he’s simply getting unlucky and will most likely trend upward in terms of his overall avg?[/quote]
Maybe. You’ve chosen an example that’s in a grey area. Based on the numbers given, it could be a legitimate change in talent level and/or adjustments made by the hitter. You need to look at other statistics in conjunction with BABIP to make a proper assessment. Looking at a players plate discipline (his walk rate, how many pitches he’s swinging at outside of the strike zone, etc) is a great place to start. When we see extremely high or extremely low BABIPs it is generally an indication of luck or lack thereof.
For instance, Eric Hosmer’s BABIP is 100 points lower than it was last year. It has recently improved, but only a couple weeks ago it was a paltry .169.
I’m fairly confident he has been unlucky to a degree without even looking at any other numbers.
Your understanding of BABIP is correct however. It is attempting to measure luck as it assumes once a ball is put in play anything can happen. Basically, whether the ball is caught or hits the grass, one side ended up getting lucky.
[quote]DBCooper wrote:
The reason I don’t like this analysis is that it doesn’t take into account what type of hitter the player in question is. [/quote]
First off, sabermetrics can never replace actually watching the games. To perform a candid evaluation you need to consider other factors that sabermetrics cannot measure. For example, the players hitting/pitching mechanics, the type of routes they take to balls, composure or “mental makeup” and body type cannot be measured without actually watching the games.
[quote]DBCooper wrote:
I think a hitter who doesn’t have a ton of power or doesn’t use the middle of the field well will not trend upward in the same way that a player who does one or both of these things will. The reason is that a hitter who uses the middle of the field has a better chance of getting base hits as opposed to one who pulls the ball more often. Balls grounded up the middle go for base hits more than balls grounded to one side of the infield or the other and a fly ball to center has one outfielder chasing it down rather than two if it is in either gap. Furthermore, a player with more power will get more hits on balls hit right at infielders because it is routinely hit harder. A ball not fielded cleanly when it is hit very hard, even if it’s a grounder, is much more likely to be a hit than an error.
So a player with power and/or who uses the middle of the field should trend upward in terms of BABIP more than a player who doesn’t have the same power or approach. Take two identical players regarding batting avg, career BABIP and their respective current averages and BABIP for this particular season. If they are both below their career numbers by the same amount, sabermetrics tells me that they should both revert to the mean in the same manner. But in real life they are not as likely to both revert to that standard.[/quote]
Again, use other statistics and not BABIP on its own. From what you’ve described I would look at spray charts from past months/years and see where this player is hitting the ball. Look at where balls were hit when they were hitting around their career average and compare it to how they’re hitting currently.
This is a good site, its pretty flexible as you can adjust the dates on the spray charts.
http://pitchfx.texasleaguers.com/batter/457763/?pitchers=A&count=AA&pitches=AA&from=4%2F1%2F2012&to=6%2F8%2F2012