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Q.  What kinds of pitchers limit batter MPH?

A.  Right off the bat, BP acknowledged Charlie Hough and Jamie Moyer as pitchers "who owed their careers" to their ability to induce weak balls in play.

I've always been convinced that SP's who were excellent at changing speed -- those with very deceptive changes and curves -- were going to run low BABIP's.

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In Fast's articles, he also suggests high velocity as a way to induce cut-down swings.  (The MPH on batted balls is almost totally caused by batspeed.  You don't get much of a bonus in batted-ball speed just because the pitch came in at 95 mph.)  

This had been the very first thing that historian James suspected as a limit to Voros McCracken's BABIP theory.  He went and checked Nolan Ryan's BABIP's, and sure enough, they were very low.  Batters cut down their swings to catch up to Michael Pineda's heater, and .... go check his BABIP.  (I didn't have any idea what it would be before typing that sentence.)

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Finally, excellent command induces weak contact.  Mariano Rivera has the most consistently low BABIP among pitchers.  Because of control.

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What you don't want, if you're looking for good BABIP, is the kind of AAAA pitcher who does everything okay but nothing especially well.  Fastball, curve, change, okay command, 5 K's, 3 BB's, that guy is going to give up 75 mph balls in play.

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Q.  Are ML teams using this MPH data to figure out who the good pitchers are?

A.  Dunno.  My guess is that if the Mariners are using it, they started using it just last year.  (Maybe Doug Fister gives up a high MPH?)

My guess is that this winter, and maybe next, there will be teams that score Moneyball pitcher signings by being ahead of the curve.  With MPH data and a newfound conviction that some pitchers have BABIP as a skill.

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Q.  Does everything in baseball now revolve around MPH skill?

A.  No, there are still going to be good pitchers who give up higher BABIP's.

But you know what, there was a time when people didn't much care whether an SP's strikeout rate was 7.0 or 5.0.  I'd say that this advance goes into that general category, a very fundamental part of the way that you analyze pitchers.

Ron Shandler had been analyzing "Mistake Avoidance" -- hit rate and homer rate -- as one of his big five skills for 20 years, but has de-emphasized it some lately.  Time to put it back on the marquee, in my judgment.

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I'll tell ya this.  Fangraphs needs two columns for pitchers, front-and-center.  (1) MPH on batted balls.  (2) Expected BABIP (xBABIP) based off MPH and GB/FB ratio.

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