Key parts of the Twins’ surprising road series win in Houston this past weekend were two solid starts from rookie right-handers Griffin Jax and Bailey Ober. Jax kicked things off Thursday with five-and-a-third innings of one-run ball to lead the Twins to a 5-3 win. Ober followed on Friday night with five innings of three-run ball, leaving with the game tied and set up for his teammates to come through 5-4 in extra innings.
Neither outing was dominant. Jax did not record a strikeout, but allowed just three hits. Ober mostly worked around trouble from seven hits and a walk. Both pitchers were touched up for home runs by the Astros’ second-ranked offense. But they were the kind of competent, competitive starts that have been in short supply too often for Minnesota this season.
Mostly unheralded as prospects — Ober ranked 22nd in the Twins system and Jax was unranked according to FanGraphs’ pre-season prospect rankings — both rookies are in extended tryouts at the major league level for the rest of 2021. Before their major league debuts both pitchers were probably more well known for things other than their pitching — Jax for his Air Force service and Ober for his 6-foot-9 height.
Nonetheless, the two are having some modest success on big league mounds. Jax’s outing against Houston was his third consecutive start allowing only one run. That stretch has dropped his seasonal earned run average from 8.66 to 5.63. Ober’s Friday start was his fourth in a row allowing three or fewer runs and lowered his seasonal earned run average to 4.99. Further cause for encouragement is that they both have even better expected ERAs according to Statcast — 4.94 for Jax and 4.34 for Ober. Obviously, those numbers are still not what either pitcher would want them to be, but they are trending in the right direction.
Both Jax and Ober work with the standard four pitch mix: four seam fastball, curveball, slider, and changeup. Neither pitcher’s fastball is traditionally remarkable. Jax averages 92.2 miles per hour and Ober averages 92.1 per Statcast. Those averages put the pitchers in the 33rd and 32nd percentiles, respectively, among all pitchers in fastball velocity. For Ober, even that pedestrian velocity is a big increase from earlier in his career. In terms of fastball spin rate, Jax has averaged 2283 revolutions per minute (56th percentile) and Ober has averaged 2180 (34th percentile).
Despite the average or below stats on their four-seamers both pitchers are using it as their primary pitch — 50.2% for Jax and 58.4% for Ober. Their decisions to rely heavily on their heaters is supported by the results they have gotten with the pitch. Both four-seamers are grading out 0.9 runs better than average according to Statcast’s run values per 100 pitches. On the Statcast Pitch Arsenal Stats Leaderboard those fastball run values rank them tied for 124th out of 524 pitchers — solidly in the top 25 percent — that have faced at least 10 plate appearances this season. In more familiar terms, hitters have combined to hit just .227 against each pitcher’s fastball.
How is it that two pitchers that have average or below features on their fastballs find themselves performing in the top 25 percent with that pitch? Is this just fluky early career small sample size noise? Maybe. After all, Jax has thrown all of 32 major league innings and Ober has thrown just 52 and a third. But, their fastballs might have some staying power. It turns out that each pitcher has some unique characteristics in their deliveries that enable their fastballs to play up relative to what their raw stuff might imply.
Jax’s Vertical Release Point
Jax was optioned to St. Paul on July 7 after his first 5 appearances (1 start) with the Twins left him with that 8.66 ERA. He made a successful start for St. Paul (5 innings, 1 run) on July 13 and returned to the Twins for a doubleheader forced spot start on July 19. Upon that return, Jax’s fastball was noticeably different than before. That day, he successfully used it to limit the White Sox’ powerful offense to one run over 4 strong innings.
Minnesota Twins’ RHP Griffin Jax’s fastball is noticeably different today.— Jeremy Maschino (@JMaschino_56) July 19, 2021
It’s got 3 inches more carry than usual today which leads me to believe he’s got his induced vertical movement back up above league average.
Glad to see he has used his time in St. Paul productively pic.twitter.com/9hMLecrea5
Jax returned to the minors and made another quality start for St. Paul on July 25. He was recalled to the Twins following the trade deadline. Successful starts against the Cardinals and Astros followed, thanks in part to that improved fastball.
A mechanical adjustment is responsible. Since returning from his early July demotion, Jax has raised his arm slot to increase his vertical release point about 2 to 3 inches.
The vertical release point data above correlates well with an increase in vertical movement on his fastball, something that he told Do-Hyoung Park he’s been trying to emphasize this season.
Statcast tracks pitch movement with the effects of gravity. The data points above are showing that Jax’s fastball has “dropped less” in his most recent outings, giving it the visual appearance of “rise” to batters. Correspondingly, the mechanical change also reduced the horizontal arm-side movement on his four-seamer. Unlike a breaking ball or changeup, less downward and horizontal movement can often be a good thing for four-seam fastballs. In the context of the rest of the league, Jax’s new fastball has above average rise.
This is a slight adjustment and difference. We’re still only talking about a few inches of change. But, those few inches are very significant when the goal is to prevent a round ball from being hit squarely with a round bat.
The trade of horizontal break for a few extra inches of rise have changed how Jax’s fastball performs. Across Jax’s first five appearances, opponents hit .293 (12 for 49), slugged .561, and averaged 91.6 miles per hour exit velocity against his fastball. He was releasing the pitch at an average of 5.55 vertical feet and generating 2255 RPMs of spin. In his three outings since getting his release point up, he’s released the pitch at an average of 5.73 vertical feet and spun it at 2326 RPMs on average. Opponents are hitting .120 (3 for 28), slugging .360, and averaging 89.6 mph exit velocity against his fastball in that span.
Ober’s Extension and Vertical Release Point
Among all pitchers to face 50 plate appearances this season, Ober has the 4th-highest average vertical location — 3.21 feet — when his four-seam fastball crosses the plate. Despite his unimpressive fastball velocity and spin characteristics, he has confidently attacked the top of the strike zone with the pitch, throwing it there at the 6th-highest rate. Altogether, Ober has thrown 512 four-seam fastballs and nearly 73% (372) of them have been at the top or above the strike zone.
A key detail that makes this approach work for Ober is the “extension” down the mound he gets in his delivery before releasing the ball. We all know every pitcher starts their delivery from the pitching rubber, 60 feet and six inches from home plate. But, not all pitchers release their pitches from the same distance from home plate. Some pitchers gain more ground toward home in their deliveries than others. Statcast measures extension to quantify exactly how much closer a pitcher’s release point is to home plate.
By shortening the distance pitches have to travel after release pitchers can decrease the time hitters have to react, which, in effect, increases the appearance of their velocity. Perceived Velocity is a stat that attempts to quantify how fast a pitch appears to a hitter by factoring the velocity of the pitch and the release point of the pitcher.
As you might expect from a pitcher as tall as Ober, he gets very good extension. The chart below plots each pitcher’s average extension on the horizontal axis against their difference in perceived and actual velocity on the vertical axis. It shows that pitchers who get more extension tend to have perceived velocity that is greater than their actual velocity.
I have highlighted Ober’s data point in the chart and it’s clear he is a standout in both measures. He ranks third among all pitchers in average extension with 7.3 feet and has the second largest perceived velocity increase (+2.0 mph) over his actual velocity. In practice, this means Ober’s 92 mph fastball looks like 94 mph to hitters because he’s releasing the ball 7.3 feet in front of the pitching rubber on average.
Ober’s extension is not the only unique thing about his delivery. You might expect a tall pitcher to have a higher vertical release point than most other pitchers. But Ober works with a low three-quarters arm slot that puts his vertical release point in the same general area as most other right handed pitchers.
The below scatter plot maps the vertical and horizontal release points of all pitchers with at least 50 plate appearances faced this season. This plot is set up as the view from the catcher’s perspective (i.e., right handed pitchers are the cluster of data points on the left side of the chart and left handers are the cluster on on the right side).
I’ve highlighted Ober’s release point location so you can see that he’s right smack in the middle of the right handed pitchers.
In this case, being in the same area as all the other pitchers actually makes Ober stand out. He’s releasing his pitches from a place you would not expect from a pitcher of his stature. His release creates a strange angle that hitters just don’t see very much. That, when combined with Ober’s extension and plus command (he has a 3.4% career minor league walk rate and grade 60/65 command per FanGraphs and MLB Pipeline scouting reports) makes his fastball much harder to hit than you might expect from its raw velocity and spin data.
★ ★ ★ ★ ★
Neither Jax or Ober figures to turn into a dominant major league pitcher. They certainly have their points of weakness. (As their ERAs attest.) Jax’s 16.2% strikeout rate is well below average. Both pitchers have been prone to home runs — 8 allowed for Jax, 13 for Ober — in their short time in the majors. But, they have some strengths to work with. If they don’t work out as starters, both have enough intriguing characteristics that they might have a chance to effectively transition to the bullpen. The front office clearly believes pitching is a numbers game. As such, they are going to let these two try to prove they can be useful pieces to the future puzzle. If they succeed, their release points will likely be one of the big reasons why.
John is a contributor to Twinkie Town with an emphasis on analysis. He is a lifelong Twins fan and former college pitcher. You can follow him on Twitter @JohnFoley_21.