For at least the last five years, Dodgers lefty Clayton Kershaw has been considered the best pitcher in baseball, and for good reason. Kershaw is the proud owner of three Cy Young Awards (2011, 13-14) and an MVP award (2014), and led the majors in ERA for four consecutive seasons between 2011-14. Since his sophomore season in 2009, Kershaw has never finished a season with an ERA higher than 2.91 and has twice finished with a sub-2.00 ERA. It’s tough to beat that.
Yet Cubs right-hander Jake Arrieta — who threw his second career no-hitter on Thursday — has been better, especially lately. As USA TODAY’s Bob Nightengale points out, over Arrieta’s last 24 starts, he has an unfathomably low 0.86 ERA with a 20-1 record. And that one loss? It took a no-hitter to beat Arrieta! Cole Hamels threw a no-hitter at Wrigley Field on July 25, his final start with the Phillies before he was traded to the Rangers.
Using adjusted ERA (also known as ERA+) from Baseball Reference, Arrieta has actually been slightly better than Kershaw since the start of the 2014 season. Adjusted ERA accounts for park factors and the quality of the pitcher’s league. In this case, since the pitchers both pitch in the National League, that isn’t really a factor. According to ESPN’s park factors, Dodger Stadium has been more pitcher-friendly than Wrigley Field.
How does Arrieta do it? He uses a four-seam fastball and a cutter, accounting for nearly 80 percent of his pitches — 50 percent and 29 percent, respectively. Hitters find him very tough to square up, making “hard” contact — in the estimation of FanGraphs’ batted ball data — approximately 23 percent of the time, the second-lowest rate since the start of the 2014 season among 85 pitchers (min. 300 innings), behind Dallas Keuchel. 53 percent of balls put in play against Arrieta have been on the ground, the eighth-highest rate.
There’s been a lot of debate lately in which some have stated that Bryce Harper has overtaken Mike Trout for the title of best player in baseball. At least when it comes to pitchers, Arrieta might be the Harper to Kershaw’s Trout.