THE BOOK--Playing The Percentages In Baseball

Very good stuff. A few tidbits I found especially interesting were the bits on Yankee Stadium in 2009 and the ‘carry’ factor in stadiums and parks.

Also, the trajectory of the batted ball - whether you would expect a home run, line drive, out, etc.

I was also there for this presentation and enjoyed it a lot.  A couple more observations:
1.  Regarding Erik’s note above, Nathan said that if the bat speed was 90 mph or more and the strike angle was 10 degrees, you would get a 90% BABIP.  And BTW at John Scherholz’ presentation we stated that he had to learn a new language as his “stat guys” now talked about BABIP, VORP, etc.  As an aside he also called the 1991 Braves the “Outdoor WS Champions”.  He explained that the Twins won all four of their games indoors, and the Braves won their three outdoors!
2.  There was a question of Rand Pendleton regarding the accuracy of the “Strike Zone” that we see on TV.  Rand stated that the width was “exact” and the height was adjusted for each hitter by their guy at the game.  With some prodding he admitted (the obvious): That when we see an ump apparently calling a strike on a pitch that was 5” outside the strike zone, the ump actually missed it by that much.

Regarding Erik’s note above, Nathan said that if the bat speed was 90 mph or more and the strike angle was 10 degrees, you would get a 90% BABIP.

That would be hit ball speed, not bat speed, and Alan was very close. Using a vertical angle of between 8 and 12 to get a reasonable sample size I calculated a BABIP of .867 from the April 2009 data that we were given last year. 

It is pretty hard to imagine how incredibly difficult it is to hit a ball at a 10 degree angle consistently.  If you are swinging the bat in a plane at a 10 degree angle you must hit the center of the ball with the center line of the bat within +- 1/40 of an inch to hit the ball between 8 and 12 degrees.  Hard enough if the ball were sitting still, but almost impossible when the ball is traveling at 90+ MPH.

Re Erik and Peter:  Yes, I did say batted (or hit) ball speed, not bat speed.  And since Peter and I were analyzing the exact same HITf/x data, we arrived at the same conclusion.

The panel was fun.  I think all of us who participated really had a good time with our presentations and especially fielding the many questions from the audience.  Although I can’t really speak for the audience, I have the impression that they enjoyed it as well.

The talks can be downloaded here:

http://webusers.npl.illinois.edu/~a-nathan/pob/SABR40Panel.zip

Note also the nice summary today by Dave Allen at
http://baseballanalysts.com/