Four Hypotheses for Matt Brash’s sudden struggling
*This story was published on May 8th 2022 in Japanese.
Matt Brash’s Raging Month
The pitcher who experienced the most intense ups and downs in the first month of the 2022 season may be the Mariners’ Matt Brash. Last season, Brash became famous among some fans as a pitcher with a high-variety slider and curveball. He first caught national attention in spring training this year, where he allowed only one run in 9.1 innings while recording 12 strikeouts.
At the beginning of spring training, Brash was considered a lock to start the season in the minors, but after this performance, the leaders changed their minds, and he succeeded in making the Opening Day roster. As a result, he made the Opening Day roster and his MLB debut on April 12 against the White Sox. Although he was the losing pitcher, he pitched well in his debut, striking out six in 5.1 innings.
In his next start against the Astros on the 17th, he recorded his first win and seemed to be steadily establishing himself in the MLB. However, he was hit for six runs in two innings against the Marlins, and he showed no signs of recovery in a game against the Astros on May 4 and was optioned to the minors.
In this post, I would like to offer four hypotheses as to why Brash, who appeared to be the savior of the Mariners pitching staff immediately after the season opener, has suddenly lost his velocity, including a comparison with Michael Kopech (CWS), a pitcher of a similar type to Brash.
Hypothesis 1: Luck doesn’t last (a swing of fortune).
Some readers may be disappointed by the first hypothesis. But luck is an essential factor. And Brash was helped by luck, especially in his second game against the Astros. Brash recorded a double play in every inning through the fourth in this game, including a strikeout gem in the first inning. In all but the first inning, the ball was in front of the fielder on three double plays. Of course, the accuracy of the defensive shifts and other factors may have played a role, but it is probably true that luck was involved.
Conversely, there was a reversal of this luck against the Marlins. Brash hit a timely shot to Jacob Stallings, but it was a batted ball (the ball’s velocity was only 67.4 mph!). ), and the ball was hit to the right side of the plate. Nevertheless, it was out of the defensive range of third baseman Eugenio Suarez, and the run was scored. If he had been able to get a double play on this play, he probably would not have scored six runs in this inning alone. This slight difference in luck must have significantly impacted Brash’s performance.
From here, I would like to compare Kopech, who, like Brash, throws a 4-seam in the low 90s and uses a slider and curveball as his main breaking pitches. Kopech, like Brash, has been a star since his days in the minors, and he made his breakthrough last year. So far this season, he has been in great form, with a 1.17 earned-run average. The following three hypotheses were developed to consider how two pitchers with similar repertoires and velocities could have such a difference in performance.
Hypothesis 2: Command is at a level that cannot fool by pitch velocity.
The first hypothesis concerns command. Kopech is also below MLB average in terms of control, with a BB% in the bottom 21%. However, even compared to Kopech, Brash’s command is poor, with a BB% in the bottom 2% of MLB, one of the worst.
His first-pitch strike rate is 63.2%, 2.5 percent higher than the MLB average. Still, in full count situations, 9 of 15 pitches he throws are balls (i.e., walks), which is 60%, which is an extraordinary figure considering that the league average is 23.3% (Kopechk threw 37 pitches on full counts, and only 8 of them were balls).
This low ability to get strikes in situations where strikes are needed may have affected Brash’s pitching.
Hypothesis 3: 4-seam that is hit despite its velocity
As mentioned earlier, Brash and Kopech have similar repertoires. As for the velocity of their 4-seam pitches, Brash’s is 95.9 mph, and Kopech’s is 95.2 mph, both of whom are among the best in the MLB. However, when looking at the batting average, Kopech is hitting .145 while Brash is being hit badly at .355.
This difference is the difference in the RPMs of their 4-seamers. Kopech throws a 4-seam with 2502 RPM, which is in the top 4% of all MLB pitchers in terms of spin. On the other hand, Blach has 2219RPM, slightly below league average.
In Active Spin%, Kopech’s is 96%, and Brash’s is 92%.
Using these numbers to calculate Active Spin, Kopech has 2502 x 0.96 = 2402 RPM, while Brash has 2219 x 0.92 = 2041 RPM. In general, the higher the Active Spin is, the more knobby the 4-seam is, and in this respect, Brush is far inferior to Kopech.
Of course, there are excellent 4-seams with low Active Spin close to a straight slider. However, in the case of Brash’s 4-seam, the RPM is only slightly below the MLB average and not extremely low, making it a rather boring 4-seam. For this reason, Brash’s 4-seam has become easy prey for hitters.
Hypothesis 4: Sliders and curves that are hit despite the amount of change
Next to the 4-seam, Brash throws a lot of sliders. This slider has been the talk of the town on social media and is famous for its horizontal movement. However, this slider has a Run Value of +6 (the run value should not be positive from the pitcher’s perspective), which is the worst number in his repertoire. In addition, the curve has a negative value of +1 as well.
But this amount of change may be why Brash’s slider is getting hammered. I thought so after looking at the approach of the only two Astros hitters who faced Brash twice, on April 17 and May 4: In the fimatchup, they swung 11 times at his slider and curve, which totaled 39 pitches, while they swung 12 times at 43 pitches in the May 4 matchup. This seems like almost no change, but five of the 12 swings in the 4th were by Chaz McCormick.
If we look at the number of batters who swung rather than the number of swings, we see a drop from seven to five. Jose Altuve, in particular, swung three times in the 17th but none in the 4th. I’ve rambled on, but I think Brash’s breaking ball has too much change and is being overlooked by hitters.
In addition to a large amount of change in Brash’s slider, 11.5 mph difference in velocity between his slider and 4-seam contributes to the that hitters are often blindsided by slider. Like Blasch, Kopech also has a significant pitch velocity difference of 11.9 mph, but Kopech’s slider has a minor change from Blasch’s.
With such a significant difference in pitch velocity plus a large amount of change, Brash’s slider may be overlooked by hitters, and he may not be able to strike out as much as he would like.
