MLB Stats: Strikeouts on the Rise

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More and more MLB stats are making their way out into the public eye; one of the many stats that has got much more attention over the years is the steady increase in strikeouts across the league since 2015. Since 2015, MLB’s league average strikeout rate has jumped up 5.7% through the early games of 2021.

Graph Source: Baseball-Savant

It should be no surprise that since 2015, the strikeout percentage across the league has gone up with the league average spin rate (image above). Spin Rate was made popular with the endorsement of the most well-known baseball development program in all of baseball (Driveline Baseball) and Trevor Bauer who was one of the first players to be involved in the topic.

Among one of the many professional groups dedicated to helping pitchers take their game to the next level, Codify Inc. Major Leaguers who are working with Codify include Marcus Stroman, Liam Hendriks, Blake Treinen, and former MLB pitcher Dan Straily who, since joining the KBO, has become one of the leagues most effective starting pitchers.

ALSO READ: Introducing SIERA, a NEW way to of measuring pitchers

2021 MLB Stats: Pitchers Are Only Getting Better

A popular opinion among baseball fan circles is the idea that MLB has a problem with the lack of action, with MLB seeing an increase in strikeouts over the previous five seasons. Some 2021 MLB stats early on will have the occasionally inflated numbers because of the obvious small sample sizes.

Hitters through the early beginnings of 2021, hitters are striking out at a 24.6% clip with a league-low .284 BABIP since 2015. The league offense as a whole has taken a dip in production through 2021:

SeasonK%BB%BA/xBASLG/xSLGBalls in PlayAverage Spin (RPM)
League Average Across Stat-Cast Era

Over the course of the Stat-Cast Era, MLB teams and pitchers themselves have come across new formulas for success on the mound. Despite the leagues increasing strikeout rate, the league has made a few changes in favor of the pitcher, with the new baseballs introduced before the 2021 MLB season. The league after the 2015 season saw the home-run rate soar; in a span of 4 years, the league home runs went from 4909 HR in 2015 to no lower than 5585 league home runs and as high as 6776 home runs over the next 4 seasons.

Why The Strikeout Increase?

A large topic of discussion regarding 2021 MLB stats and all years in general, since the beginning of the 2015 season, the league has seen a combination of pitches get slowly phased out of some team’s repertoires.

Chart Source: Baseball Savant

Since 2015, sinkers and two-seam fastballs haven’t necessarily gone away, they’re just not as effective as people think. Some of the teams with the highest percentage of sinkers and two-seamers thrown include Pittsburgh Pirates, Oakland Athletics, Texas Rangers, New York Mets, and the Chicago Cubs, rounding up the top five (not in order).

Among the teams who rank near the bottom since 2015, including the Tampa Bay Rays, Houston Astros, Cleveland Indians, and the Los Angeles Dodgers. One of the biggest examples after ditching the sinker for success is Gerrit Cole before being traded before the 2018 season. Now we all know how that has worked out, and the Astros scandal obviously dirties the attitude involving the situation. But these teams have all had success over the years with bringing out the best in pitchers using an increased percentage in elevated fastballs.

Tampa Bay Rays starting pitcher Tyler Glasnow is just another pitcher who, by coincidence, comes from the same team that dealt Gerrit Cole. Glasnow, who has 211.1 innings in his time in Tampa, has an impressive 3.02 ERA and 3.10 FIP, compared to his 5.79 ERA and 4.90 FIP, will look to continue the additional success since joining the Rays.

Now as previously mentioned, the league is cutting down on its sinker and two-seam usage, BUT, the location of the pitches is also something that deserves recognition:

The chart on the left is fastballs thrown down the heart of the plate and on the right, we have elevated fastballs in the zone. Again, the league isn’t completely getting rid of sinkers and two-seam fastballs, the pitches just aren’t as effective as they seem or use to be. The game over the years has evolved around the ability to strike batters out, and that game plan doesn’t look like it will be changing any time soon.

main image credit Embed from Getty Images

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Murray is a college student attending Humber College for Sport Business, can be found on Twitter at @_MurrayBrown