Wednesday, August 04, 2010
Leaders in kwERA
Posted by Mike FastI've been watching Joaquin Benoit's season as the set-up man for the Tampa Bay Rays. In case you haven't noticed, he's been putting up some pretty nice numbers: an ERA of 0.70 and a WHIP of 0.55. He has struck out 53, walked six, and allowed 15 hits and three runs, all on solo home runs, in 38 innings.
That's a pretty nifty strikeout-to-walk ratio, no?
A few years ago, Guy M and Tom Tango came up with a neat toy called kwERA that works a little bit like FIP, except that it ignores a pitcher's home run rate. It's a measure of strike zone dominance.
The formula is kwERA = 5.40 - 12 * (K-BB)/PA. Here are the leaders in kwERA in 2010 for all pitchers with at least 30 innnings.
Pitcher ERA IP TBF BB SO BB/PA K/PA K-BB/PA kwERA Joaquin Benoit 0.70 38.1 133 6 53 0.05 0.40 0.35 1.16 Luke Gregerson 2.41 52.1 190 9 66 0.05 0.35 0.30 1.80 Billy Wagner 1.77 45.2 178 14 66 0.08 0.37 0.29 1.89 Carlos Marmol 2.50 50.1 214 34 94 0.16 0.44 0.28 2.04 Joel Hanrahan 3.40 47.2 191 14 67 0.07 0.35 0.28 2.07 Stephen Strasburg 2.32 54.1 217 15 75 0.07 0.35 0.28 2.08 Rafael Betancourt 4.89 38.2 165 5 49 0.03 0.30 0.27 2.20 J.J. Putz 1.83 39.1 149 7 45 0.05 0.30 0.26 2.34 Matt Thornton 2.43 40.2 163 13 54 0.08 0.33 0.25 2.38 Edward Mujica 2.74 49.1 185 4 50 0.02 0.27 0.25 2.42Jered Weaver leads the full-season starting pitchers with a kwERA of 2.86 on the strength of 162 strikeouts and 35 walks in 601 batters faced. Francisco Liriano and Cliff Lee are not far behind at 3.00 and 3.11, respectively.
I did a thorough but not completely exhaustive search for the best kwERA seasons of all time, and based on that, I'll hazard a guess that Eric Gagne in 2003 wins the prize. His 137 strikeouts and 20 walks in 306 batters faced produced a kwERA of 0.81.
Gagne's 2003 campaign is followed by Billy Wagner 1999 (1.16), Brad Lidge 2004 (1.27), Pedro Martinez 1999 (1.43), Eric Gagne 2002 (1.65), Pedro Martinez 2000 (1.70), Jonathan Papelbon 2007 (1.70), Randy Johnson 2001 (1.77), Pedro Martinez 2001 (1.77), and Joe Nathan 2006 (1.78).
Almost all the top seasons in this metric have occurred since 1990, with the exception of Tom Henke's 1987 season, wherein he notched 128 strikeouts against 25 walks in 363 batters faced, for a kwERA of 2.00. Reaching back a little further in baseball history, we find Bruce Sutter's 1977 season, with 129 strikeouts and 23 walks in 411 batters faced, for a kwERA of 2.31, and Sandy Koufax's 1965 season, with 382 strikeouts and 71 walks in 1297 batters faced, for a kwERA of 2.52.
To move back further in history, we go all the way back to Hugh "One Arm" Daily and his 1884 season with the Chicago Browns, Pittsburgh Stogies, and Washington Nationals. Daily recorded 483 strikeouts and 72 walks in an estimated 2076 batters faced. That computes to a kwERA of 3.02, though I doubt Tango constructed the formula to work for the Union Association days of yore.
Mike Fast is a Royals fan who enjoys investigating baseball questions using data of many sorts. He is a member of Complete Game Consulting. He welcomes comments via e-mail.
Neat! That was a decent little 3-year run that Pedro had from 99-01, no?