A year ago, I predicted an ERA improvement in three pitchers based solely on their swinging strike rate. Those three, Tim Lincecum, Jeff Samardzija, and Cole Hamels, were names familiar to baseball fans and success was sure to find their way again. Perhaps emboldened by correctly identifying two players whose performance drastically improved in 2014 (both Hamels and Samardzija saw their ERA’s drop more than a full run), I re-ran the exercise for the 2014 season, in the hopes of identifying the next breakout candidates.
The concept is simple: the more bats that you miss, the better you pitch. Of course, there will be outliers and there’s the old man school of thought that tries to induce weak contact. Pitching philosophy aside, there’s a correlation between missing bats and ERA and the graph below displays that. I plotted ERA and Swinging Strike rate against each other and found the line of best fit amongst the 2014 data. More simply, the line is what you might expect a pitcher’s ERA to be based on their Swinging Strike rate, or vice versa.
Clay Buchholz is the obvious bounce back guy this year. His 2014 performance was poor in no small part because of injuries, but also because of an adjustment in his delivery that was supposed to improve command. Buchholz never got comfortable with the change and ultimately wound up with the worst ERA of his career. What’s most interesting here is that Buchholz walked fewer guys and maintained a swinging strike rate on par with his career norms. The 30 year old just didn’t find the success that he had in his first 6 major league seasons.
Ervin Santana was awarded a $55 million contract this offseason by the Minnesota Twins. He’s 32 years old and coming off a season in which he threw 196 innings to the tune of a 3.96 ERA – worth just 1.2 bWAR. He’s had injury concerns and his heavy reliance on his slider does little to quiet the skeptics. But, Santana missed bats last year more often than Zack Grienke, Max Scherzer, Stephen Strasburg, and Madison Bumgarner. He’s long had fantastic stuff, but the transition from NL East to AL Central makes me slightly less confident in Santana reaching the ERA that his swinging strike rate would indicate.
Finally, Drew Hutchison. The 24 year old Hutchison underwent Tommy John surgery in August 2012 and entered Spring Training last year competing for a spot in the rotation. Hutchison went on to finish 8th in the AL in strikeouts and k/9. He missed plenty of bats throughout the year and looks like the type of pitcher who could gain that extra bit of command and take the “next step“.
Hutchison is the guy that I feel most confident in among the three listed here. Buchholz will inevitably improve, but remember that even a 4.3 ERA in 2015 would represent a full run’s improvement. Santana is 32 and seems to have a history of incredible stuff that doesn’t quite add up. A normal offseason should help Santana, but does a sub-3 ERA really sound reasonable? In the AL Central?
Hutchison will get to face division rivals that sport lineups with a few holes, and is an unproven commodity at still just 24 years old. I’ll withhold from super bold predictions, but the stuff indicates an ERA closer to 3.2 than 4.5.
Finally, just as a proof that this excercise isn’t completely ill-founded, I highlighted Clayton Kershaw. The best pitcher in the world also lead the Majors in Swinging Strike rate. The model thinks he’ll have an ERA of 2.55. That’s fine, but the computer doesn’t realize that Kershaw hasn’t had an ERA that high since 2010.
-Sean Morash
Stat of the Day: Neither Drew Hutchison nor Hisashi Iwakuma allowed an unearned run in 2014. They were the only qualifying pitchers to do so.
