THE BOOK--Playing The Percentages In Baseball

Wednesday, April 01, 2009

Prof Pepper

I linked to his great work on Chase Utley.  And then I completely forgot about him.  No more.  He’s now on my main blog list, so I’ll be checking him out at least weekly.  Here are some of the fascinating posts of his I’ve already missed:

Bad-ball swingers

As we see from the table, Gary Sheffield is the only player in MLB to have a positive value for his bad pitch swinging (at 29% his swinging percentage on bad pitches is middle-of-the-pack). Jose Reyes, the worst in this ranking, has lost 32 runs by swinging at balls way out of the zone. Players like Ryan Howard and Vladimir Guerrero can have a gross production of more than 11 runs when swinging at bad balls, but when you look at what they would have produced had they let those pitches go by you get a net loss of nearly 30 runs.

I’ll have to check his process, but he has the same basic idea I have, and that Dave Allen had.

ARM 2.0, where he does a smoothing function:

This time I add the location information. Ideally I want to have the average run value at every possible location where a right fielder can collect a single. Obviously there can’t be enough observations to have every single point on the field covered, thus I used loess smoothing. Very quickly on loess smoothing: you estimate the (run-)value of every point on the field using the run values of points in the neighborhood which have observations - nearer points have more weight on the estimation.

Predicatability of pitchers:

High Theoretical Predictability
pitcher MLP repertoire
Tim Wakefield 99.7% KN-FB-CB
Grant Balfour 86.2% FB-SL-CH-CB
Jonathan Papelbon 78.7% FB-SL-CH-SF
Neal Cotts 76.7% FB-SL-CH-CB
Matt Thornton 76.4% FB-SL-CT-CH
Brad Ziegler 75.2% FB-CB-SL-CH
Dennis Sarfate 69.7% FB-CB-SL
David Riske 69.5% FB-CH-SL
Joe Beimel 69.4% FB-CB-CH-SL
Daniel Cabrera 68.9% FB-SL-CH-CB

Low Theoretical Predictability
pitcher MLP repertoire
Andy Sonnanstine 24.1% FB-CT-CB-SL-CH
R.A. Dickey 24.2% KN-FB-CB-CH-SL-SF
Jorge Campillo 26.9% FB-SL-CH-CB-CT
Shaun Marcum 27.0% FB-SL-CH-CB-CT-SF
Bronson Arroyo 27.2% FB-CB-CH-SL-CT
Carlos Villanueva 27.2% FB-SL-CH-CB
Mike Mussina 28.1% FB-CB-SL-CH-SF
Doug Davis 28.7% CT-FB-CB-CH-SL
Lance Cormier 29.2% CB-SL-FB-CT-CH
Jered Weaver 29.7% FB-CH-SL-CT-CB