Chris Archer’s Sinker Has Him Sinking
Do you remember when Chris Archer was really good at throwing baseballs? You should, because it was very recent! From 2014-17, only 12 pitchers across the majors accumulated more WAR than Archer. He was a strikeout maestro who kept his FIP consistently low with a knack for gobbling up innings and a sweet head of hair to boot, looking like an ace in pretty much every sense of the word.
Those days feel far away now, however, after a disastrous start on Tuesday brought his rough season with the Pittsburgh Pirates to a crescendo — he surrendered five home runs to Braves hitters in six innings, leading to an ugly seven-run outing. He has now allowed 16 homers in just 59.2 innings, giving him the fifth-highest HR/9 rate among all big leaguers with at least 50 innings pitched. His ERA of 5.79 is actually outperforming his 6.15 FIP. The old Archer seems long gone, but what caused him to vanish?
Typically, when a player regresses this swiftly and severely, there can be multiple issues to blame for their struggles. If you squint, you can see a few present with Archer. His four-seamer has lost two miles per hour in velocity over the past two seasons. He’s also throwing fewer strikes than he has in past years — something that is evident in his skyrocketing walk rate, up at 4.53/9 from a career average of 3.03/9 — but just 1.5% less than his career average. We can nitpick and analyze a million different data points to paint a picture of why Archer has lost his groove, but instead, let’s just talk about the issue right in front of us: His sinker has been absolutely dreadful.
I’ll admit his sinker has accounted for just 22% of his pitches this season, and that’s if you go by Baseball Savant’s pitch tracking. Our own Pitch Info data says he’s thrown it less than 15% of the time. How bad can a pitch be to be singled out as possibly the biggest cause of a player’s struggles if he throws it with less than one quarter of his pitches? In this case, extremely bad! In 2019, Archer’s sinker has resulted in a .370/.485/.815 slash line for opposing hitters. The Statcast data for the pitch is equally gruesome: .403 xBA, .761 xSLG, .522 xwOBA. Read the rest of this entry »