Chris Sale has been an extremely good pitcher over the past few seasons, but future games are not won on past performance. Are there any signs that Sale might be trending downward?
In the past two seasons, Sale’s ERA and ERA- have been relatively high, compared to his previous seasons. By ERA-, his worse season was 2015 (84), with 2016 only slightly better (78); by comparison, his previous three seasons were 72, 76, and 56:
His strikeouts per nine innings were also down in 2016, from a league-leading 10.8 in 2014 and 11.8 in 2015, to 9.3 in 2016. In terms of pitch value, his renowned slider took a significant step backward in 2016; the total bases per 100 pitches for the pitch increased from 5.5 in both 2014 and 2015, to 7.4 in 2016:
His fastball also showed a slight velocity dip in 2016, compared to 2015:
However, none of these changes seem particularly concerning. The velocity dip is simply a return to his normal speeds, because his velocity in 2015 was slightly higher than usual. (The increase in velocity of his changeup might be slightly more troubling, since it reduces the velocity difference between his changeup and fastball. However, 6.8 mph is still a reasonable amount of separation between the pitches.) An ERA- of 78 is still far better than average, and the slight bump in TB/100 for his slider does not seem to reflect any loss of pitch movement. The chart below shows the overall amount of break – as well as the amounts of component horizontal and vertical movement – on each of his pitches since 2011, with the dots scaled proportionally to the number of each pitch type he threw that year:
In 2016, his slider gained even more vertical movement than in previous years, without sacrificing its extreme horizontal movement.
In all, any apparent trends to reduced effectiveness are probably an illusion based on Sale’s dominant 2014 season, when his 2.17 ERA set a career best and his 173 ERA+ led the AL. His 2015 and 2016 seasons, while falling short of 2014, were still well above average, and are in line with his overall career.
On the other side of the coin, Sale should benefit from playing with the Red Sox rather than the White Sox. In 2016, Sale’s catchers were Dioner Navarro, a truly horrendous framer, and Alex Avila, a very bad one. Red Sox catchers are average to very good at framing, which could add an extra 1 to 4 strikes per game to Sale’s results from framing alone. Defensively, the Red Sox outfield represents an upgrade over the White Sox’s 2016 outfield, with Mookie Betts roughly equalling Adam Eaton while Jackie Bradley Jr. and Andrew Benintendi far outstrip Melky Cabrera and J.B. Shuck.
The Red Sox may not see another 170 ERA+ season from Sale, but Clayton Kershaw is the only pitcher for whom that’s a realistic expectation. Sale shows no sign of injury, and it does seem reasonable to expect him to pitch to his career averages over the three years he is under Red Sox control.