Has Ditching the Sinker Worked for Pitchers?

Earlier this year, Travis Sawchik urged baseball fans to go see the two-seamer before it’s gone. A year ago, Alex Stumpf discussed the death of the sinker. Over the years, pitchers have chosen to de-emphasize a sinking fastball, instead opting for breaking pitches and four-seamers. The sinker has never been a swing-and-miss pitch, and as pitchers have gotten better, they’ve been more able to utilize offerings more likely to lead to a strikeout. While the change has been a gradual one overall, there are a certain number of pitchers every season who make dramatic changes to contribute to the downward trend.

Last season, 55 of the 134 pitchers with at least 100 innings threw a sinker at least 25% of the time. This season, the number of pitchers throwing a sinker that often has dropped by nine percentage points, pretty clear evidence of the sinker decline. Let’s focus in on the sinkerballers from a year ago. This season, 36 of the 55 sinker-throwers from a year ago have pitched at least 50 innings this season. Nearly half of those pitchers have dropped their sinker use by at least four percentage points and nearly one quarter have dropped usage by more than 10 percentage points.

Before getting to the pitchers who have made changes, let’s set something of a baseline, focusing on pitchers who have kept roughly the same usage as last season for both their four-seamer and two-seamer. Here are those pitchers as well as the change in their strikeouts, walks, ERA, and FIP from the previous season.

Overall, this group wasn’t quite as good as they were a year ago. Strikeouts went up slightly, but walks have gone up more. Alex Cobb is responsible for a jump in ERA, but a handful of players contribute to the increase of FIP from last season. Given the number of older players, we might just allocate the difference from 2017 to normal aging.

I’ve separated the two-seam decliners into two groups. The first group isn’t all that big, consisting of players whose sinker usage has declined without a corresponding increase in four-seam usage. The change in usage can be seen below.

These pitchers are just throwing the fastball less often. Mike Leake is throwing more changes; Alex Wood, Jhoulys Chacin, and Clayton Richard more sliders; and Sonny Gray more curves. The change in repertoire has had mixed effect.

Gray has had some trouble throwing fewer fastballs, Leake is now pitching a full season in the American League. Richard and Wood are having solid seasons. The ERA is up overall and walks are, as well, but given the similar FIP and the small number of pitchers, there really isn’t much to go on here.

Next, we have the group of pitchers who have shifted from the two-seam fastball to the four-seam fastball. The table below shows the change in pitch selection.

We see three different Pirates, a couple of Astros, some younger pitchers in Mike Foltynewicz and Aaron Nola, and a few players who have switched teams in the last year like Jose Quintana and Lance Lynn. Here’s how these pitchers have performed this year.

Strikeouts are up nearly two percentage points, and that’s likely what the pitchers intended when they moved to more four-seamers. Walks are up a bit, as well, as pitchers move from a pitch intended to produce contact to one they hope hitters chase. By FIP, Nola, Ivan Nova, Kyle Freeland, Lynn, and Foltynewicz have all seen improvement. Charlie Morton is still pitching well with Dallas Keuchel about the same and Jameson Taillon not too far from last year’s results. Chad Kuhl and Quintana are the only pitchers who have produced significantly worse results. This isn’t to say trading sinkers for a fastball that stays up will work for every pitcher, but the pitchers who have done so this year have had some success with it.

If you were paying really close attention, you might have counted the pitchers above and noted that six pitchers have not yet been accounted for. Those six pitchers have seen a significant decrease in four-seam fastball usage from 2017 to the present year, bucking current trends.

While everyone else zigs, Corey Kluber seems to have zagged by throwing more sinkers and fewer four-seamers. It seems to be working for him. Carlos Martinez has added a cutter, which has reduced his four-seam usage. Rick Porcello is using his slider more. Gio Gonzalez has used more changes and sinkers while Lance McCullers Jr. and Mike Montgomery are upping their changes. Here’s how those pitchers’ numbers have changed since last year.

Not a whole lot to see here, with Porcello rebounding after a disappointing season, Kluber pitching really well again, and the rest pitching in line with where they were last season. The clear winners among sinkerballers are those who were able to shift usage to a four-seamer. These players didn’t stop throwing a sinker, but throwing more pitches with the swing-and-miss in mind seems to have been effective. It probably won’t work for all pitchers, but it is probably something worth exploring.