The legend of Dave Duncan is well known. Pitcher A stinks and is released by his current team. The Cardinals sign Pitcher A and he miraculously becomes a good pitcher. Dave Duncan’s effect on these pitchers can be seen in the groundball rates. Another NL Central pitching coach has a similar effect on pitchers’ strikeout rates. Every year from 2001-2008, Cubs’ pitchers led all teams in strikeouts. In 2009 they finished tied for second. The northside pitching staff has seen plenty of turnover throughout those years, but the one thing that hasn’t changed is Larry Rothschild. He has been the Cub pitching coach since 2002.
So does Rothschild really have an impact on his pitchers’ strikeouts. To find out I compiled a list of all pitchers the Cubs acquired from outside the organization between 2002 and 2010. According to the Sabremetric Library, K/PA becomes reliable after 150 batters faced. After limiting my list to only pitchers who faced 150 batters as a Cub, I found their K% before they joined the team and during their time with Rothschild. Here is the list.
Pitcher K% Before K% After Difference
Matt Clement 17.60% 23.20% 5.60%
Antonio Alfonseca 14.70% 17.90% 3.20%
Shawn Estes 17.90% 14.70% -3.20%
Mike Remlinger 22.30% 24.80% 2.50%
Greg Maddux 17.20% 15.50% -1.70%
Glendon Rusch 16.70% 17.20% 0.50%
Latroy Hawkins 14.70% 19.90% 5.20%
Kent Mercker 15.60% 22.90% 7.30%
Ryan Dempster 18.00% 21.10% 3.10%
Jerome Williams 14.70% 12.30% -2.40%
Bob Howry 20.30% 21.00% 0.70%
Scott Eyre 17.00% 23.60% 6.60%
Ted Lilly 19.60% 20.60% 1.00%
Jason Marquis 13.90% 12.60% -1.30%
Neal Cotts 19.90% 22.70% 2.80%
Rich Harden 23.30% 29.10% 5.80%
Aaron Heilman 20.40% 20.80% 0.40%
Kevin Gregg 20.80% 23.80% 3.00%
Tom Gorzelanny 14.80% 23.70% 8.90%
John Grabow 20.50% 15.30% -5.20%
Carlos Silva 9.80% 17.30% 7.50%
Only 5 out of the twenty-one pitchers in the list saw their K% decrease under Rothschild. I assume Maddux didn’t learn anything he didn’t already know. Clement, Gorzelanny, and Silva are the big ones. Clement’s three best years were with the Cubs, and Gorzelanny and Silva were borderline major leaguers when they arrived in Chicago. Even though he had Kerry Wood, Mark Prior, and Carlos Zambrano during the strikeout streak, we need to give Larry Rothschild credit for his influence on the high strikeout totals.