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Friday, March 12, 2010
Changing the plane of a hitter’s swing
Jeff is dead right:
Let’s look at the breakdown statistically. Gomez’s career wOBA on grounders is .286, on flies it is .230, and on liners it is .689. Converting into runs, every fly ball he turns into a ground ball is worth about 0.05 runs. Every line drive he trades for a ground ball costs his team about 0.25 runs—a sacrifice of five times as much as the benefit gained by each fly-turned-grounder.
(Actually, .35, not .25.) But, yeah, just a fantastic point to make. The key plane of the swing is to get line drives. This is true for any hitter. For some hitters, you alter the plane slightly to get more FB and others to get more GB. But, you can’t live and die on the groundball. You’ll die.
Juan Pierre is .221 on GB and .159 on FB. He can’t be such a GB hitter that he throws away all his line drives and the .658 that comes with them. So, I’m very interested in these hitter experiments, but these I presume are going to be slight adjustments, not wholesale changes.
You can’t live and die on the ground ball, but I would think that the idea of trying to get a guy to hit more ground balls is to turn line drives and some fraction of fly balls into ground balls, and some other fraction of fly balls into line drives. In other words, shifting the distribution of angle off the bat towards ground balls. In doing so, you might actually wind up with more line drives instead of fewer.
So while it is right to say that he gets killed for every line drive that becomes a ground ball, if he turns more fly balls into line drives, you get a net gain. This is exactly the kind of thing that Hitf/x is made for in my opinion.