The value of a batted ball
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The Hardball Times found this 9/20/2007 on www.hardballtimes.com [flag] |
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MLB
Comments (10)
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David Gassko I did include fliners. Unfortunately, we have less than two seasons with fliners separated out, and I didn't want to make the sample size too small. However, that is definitely something that needs to be looked into.
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writerhoward Interesting topic.
What do you mean by the "value of a batted ball"? How do you determine that?
writerhoward
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David Gassko Sorry, I can't believe I didn't explain that in the article. The value of a batted ball is simply its linear weight value -- that is, roughly .47*1B + .49*ROE + .77*2B + 1.06*3B + 1.39*HR - .25*Outs - .84*GIDP (I don't remember what exact values I used).
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tangotiger The article was skimpy on the specifics. Guys like me who are immersed in the data can appreciate it, but someone off the street (or internet cloud) will wonder what "value of a batted ball" means.
A "line drive" is not a "line drive", as if it was some discrete play, separate from GB or FB. There is a continuum scale, with non-static demarcation points. Maybe we can agree on 70% of line drives being line drives. But, a LD that just lands outside the infield dirt could easily be considered a "GB". And a LD off the wall could easily be a "FB". And a 200 foot difference in where a ball lands should hardly be lumped into the same category, as it would with a "LD".
While obviously, overall, this effect is muted, but I would suspect that if you looked at the average distance of Line Drives by Juan Pierre and Albert Pujols, that it would make a huge difference.
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gteasy Two factors come to mind...defensive alignment and hitting the ball where it's pitched.If a hitter uses a singular approach at the plate, scouts will set the defense accordingly, and the pitcher has the option of pitching into the hitter's pattern. Conversely, when hitters go into slumps it's often a case of pulling off the ball and failing to stay back. Balls on the inside half are pulled foul, and outside pitches are difficult to square up. Pitchers love this.Hitters are more dangerous when they can drive the ball to the opposite field. Pedro Feliz, for example, has enormous power to right-center, but flails with the breaking pitch in the pull mode. Ichiro hits the ball where it's pitched while seemingly on the move. With his speed it makes it impossible to set a defense. Since the beginning of baseball time, the way to break a slump is to focus on hitting the ball where it's pitched, stay balanced, and stay back.GteasySausalito -
MGL As was already pointed out above, as soon as DG reported a decent y-t-y correlation for line drive value, the first thing I thought was, "Of course." As Tango pointed out, Pujols' line drives are going to be harder and longer than Eckstein's. Not to mention the line drive home runs which are virtually only hit by power hitters.
And if he thought (likely incorrectly) that it was mostly due to park effects, why not look at players who switched parks from one year to another?
One has to be very careful with drawing certain conclusions or inferences based on correlations between two sample groups of data. For example, let's say that all the players in your sample have about the same speed, save one (we'll call him Ichiro). Overally, your correlation on ground ball value is going to be near zero (it will probably still be a little positive, as the better hitters will hit harder ground balls), but for that one player (the fast one), he will consistently have a higher GB value than everyone else. IOW, a correlation based on a sample of players does NOT necessarily tell you anything about an individual player in that sample, especially if there are a few players in that sample who have unusual qualities that affect the performance you are measuring. Now, if you don't know anything about an individual player, then you can correctly conclude that that player likely has little skill wrt to the performance in question. But if you know something about that player (like he hits lots of ground balls to the opposite side, or he is very fast going from home to first), then you can throw the correlation out the window.
Finally, David also missed the reason for the fairly low correlation wrt bunting for a base hit. Game theory! The more a player bunts, the more the defense must play for the bunt, and less successful he will be (relative to a stable defense). IOW, this will push the regression line towards a slope of zero, which is (at least somewhat) the case with all things that implicate game theory. For example, if a player is only a decent bunter and not that fast, he can bunt every once in a while and probably succeed 50% or more of the time. If he bunts any more than that, the surprise element will decrease and his success rate will probably go below the BE point. When Pierre is at bat, the third baseman is playing so close that no matter how good a bunter he is or how fast he is, his bunt rate is only going to be 45% or so, still greater than HIS BE rate. So if the guy who is a poor bunter or not fast bunts once or twice a year and is successful 55% of the time and the fast, good bunter bunts 30 times a year and is only successful 45% of the time, what do you think the correlation is going to be? In fact, I am surprised it was that high.
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thumble While game theory is an interesting approach,I think you are missing a key point about bunts. Unless you are Nick Punto, the bunt has a pre-determined outcome and that is a groundball. Take into consideration that many bunts are intended to create a "productive" out for the team employing it and the noise overwhelms the analysis. Bunts are not the same as the typical batting event and shouldn't be analyzed with the same approach.
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gteasy What drives the baseball? I ain't no physicologist, but I'm guessing that it's a combination of bat speed, mass, and the coefficient of restitution(COR) of the bat combined with the compression of the ball. Of these, bat speed is the most significant.Years ago you never saw a Barry Bonds, choking up on a light and fairly short bat. There were no Ichiro's because moving in the box was discouraged. Bats were thicker and heavier. Remember the Nellie Fox 33?Hitters today are much stronger, and the bat is lighter and possibly harder(maple?). Tension in the ball(liveliness) goes up and down. I think we can safely say that the average bat speed is at an all-time high.The higher the bat speed, the higher the chance of a hit once you make contact. Ground balls get through the infield more quickly. Line drives come off the bat faster, fly balls carry further and find the deepest reaches of the park and beyond. Players with slower bat speeds, like Dave Roberts and Omar Vizquel, have to hit the ball on the ground or on the line to have a chance at success. That's why the Dodgers coached Maury Wills and Junior Gilliam to be ground ball hitters. But Matt Holliday's ground balls will get through the infield more often because he swings a faster bat.Ichiro becomes almost the perfect hitter because he combines high bat speed(power) with contact, dispersion(all fields), and elite speed to first.GteasySausalito-
thumble I ain't no physicologist either, but force = mass x acceleration. Bat mass and bat speed matter in equal amounts and there is an optimal combination of those factors for each player.
That said, bat speed is just one of many contributing factors to the outcome of a batted ball and not all of those are the sole domain of the batter.
Knowing anything about batted ball outcomes, I would fire a coach that directed a player to hit more grounders on purpose. All that great speed would be better put to use getting gap doubles and triples.
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Links (1)
Data recorders fit square pegs into round holes
Published 9/20/2007 by Tangotiger (tangotiger@yahoo.com) at THE BOOK--Playing The Percentages In Baseball
... David’s fine article will serve as the impetus for my diatribe: ...
Nice job, David. A question and a comment:
- Did you take pitchers out of the bunting category? I assume you did, but just checking.
- I think there are definitely some hitters who get more out of their line drives than others. For instance, some batters hit more home runs off line drives than others. Also, line drive refers to the trajectory of the ball, not how hard it is hit. Naturally, some batters hit the ball harder than others, even line drives. My bottom line is that I'm not surprised at all that some players show a consistent "skill" at getting value from their line drives.
For your line drives, did you include fliners? It might be interesting to look at pure line drives (most line drive home runs are fliners) to see what things look like.