The sinker is continuing its slow fall

The sinker has long been a staple in the repertoire for major league starters. Even recently, the league-wide usage of the pitch peaked. Since pitch tracking began in 2007, the 2012 season holds the record for the highest rate of sinker usage, reaching a high-mark of 22.5 percent. Since then, though, the usage has began a slow fall, and it looks like it could be heading for near extinction at the rate it’s going.

This topic has been covered numerous times by the great people over at Baseball Prospectus, most recently by Gerald Schifman. He pointed out how not only the usage of the pitch has changed, but how the distribution has seen a major shift.

“This year, 62.2 percent of pitchers are throwing sinkers less than 10 percent of the time. Back in 2012, 40.6 percent of pitchers turned to the pitch that infrequently. It means that pitchers who barely use the sinker are now baseball’s clear majority on the mound. At the same time, those who rely heavily on the pitch are disappearing from baseball. In 2012, 21 percent of pitchers threw sinkers with at least 40 percent of their offerings; in 2019, the rate has dwindled to 10.8 percent.”

Back in September, Matthew Trueblood offered a hypothesis for this trend.

“As teams breed young pitchers, however, they’re not looking for guys to manipulate and sequence with multiple fastballs. They want, and are succeeding with, guys who can spin four-seamers up in the zone and sliders or curveballs that break hard off that plane. Bryse Wilson of the Braves entered pro baseball as a sinker-first guy. He’s now gassing people up with high mid-90s four-seamers, pairing that with a hard changeup and a two-plane slider, and that has helped him reach the majors at a younger age than any other pitcher since Julio Urias.”

So far, it has been inarguable that sinker usage and its fall have reached an all-time high in 2019. In the pitch-tracking era, we are now at a new low in sinker usage for the second straight season. The pitch has seen its biggest change in usage this season and its not even close. The three percent fall is by far the biggest shift in usage in either direction, with the previous high being the 1.7 percent decline between the 2015 and 2016 seasons.

To break it down further, I wanted to look at the historical data for the trends of where sinkers are heading velocity-wise. In 2008, 28 percent of pitchers threw their sinkers in an 86-90 mile per hour velocity range. That rate this season currently stands at 23 percent. Also in 2008, sinkers were topped in the bucket of 91-95 miles per hour, at 42.4 percent. That range still tops this season too, but is even higher at 47.7 percent. As for the rarest velocity range, the 96 and up mile per hour bucket, only 2.7 percent of sinkers in 2008 were thrown in that range. But in 2019, the rate of that range is at presumably an all-time high of 8.9 percent.

The top seven sinker percentages among pitchers with at least 25 thrown this year all hone above-average velocity on it: Scott Alexander, Zack Britton, Brandon Kintzler, Jose Alvarado, Jonny Venters, Craig Stammen.

It’s not hard to see why sinker usage is declining too. In the age where velocity rules, it’s harder to get by with a slower fastball. And with velocity ticking up exponentially on four-seamers, their value league-wide has been steadily growing. That effect hasn’t existed with the sinker. Prorated pitch values have reached another low for the sinker in 2019, as they’ve taken a considerable dip. The previous low-value was -0.31 in 2009. Last year it was -0.26. This year, it currently stands at -0.41. Meanwhile, four-seamers have continued their recent improvement. Last year, their value was at a high-mark of -0.04. Right now, it currently stands at -0.03.

The differentiation between the two fastballs in growing.

There’s no reason to believe that this trend won’t continue for the rest of this season and following seasons. Pitchers are now being developed to where they have no need for a sinker in their repertoire. Hitters are hitting them better and hitting four-seamers worse. The usage sinker will continue to fall.

Patrick Brennan loves to research pitchers and minor leaguers with data. You can find additional work of his at Royals Review and Royals Farm Report. You can also find him on Twitter @paintingcorner.