
The power shifts back to the hitter Monday. More specifically, the power shifts back to Trent Grisham.
Or at least that is the way the Padres’ center fielder is hoping it will all pan out this week as Major League Baseball tries to level the playing field.
As the league cracks down on pitchers’ use of spin rate-enhancing substances, Grisham has the most to gain in the Padres’ lineup from seeing the souped-up fastball spin rates come down and hitters getting a small reprieve.
Through 74 games, the third-year player has had an inexplicable difficulty hitting the fastball. Much of it, statistically speaking, can be directly attributed to the rising spin rate of the four-seamer across the league.
Starting Monday, umpires will be checking pitchers during games for all the substances that have become household names in recent weeks — Spider Tack, Pelican Grip, Tyrus Sticky Grip and whatever else is being used to have the MLB spin rate on the fastball rise by nearly 400 revolutions per minute in one year.
The enhanced spin rate affects all pitches. However, it is acutely seen in the fastball. When RPMs go up on the four-seamer, the way hitters see the ball changes. To a hitter’s eye, the ball appears to rise. It affects perception and punishes averages.
Across the league, the average on four-seam fastballs in the middle of the zone below 2,400 RPMs is .330. The average on balls in that part of the zone spinning at above 2,500 RPMs is .285. It has transformed what once was a hitter’s pitch into a juggernaut for power pitchers.
And for some fastball hitters, like Grisham, the drop-off has been even more troubling.
Grisham sees the second most fastballs on the team at 63.8 percent. The only player who sees more is Jake Cronenworth, who leads the National League in fastballs against.
The difference between Cronenworth and Grisham, though, is the infielder has batted .284 against the pitch in 2021. Grisham’s average has plummeted to .213.
It is also the case that Grisham’s drop in average parallels perfectly with the increase in RPMs. Grisham’s average on the fastball has dropped by 73 percentage points in the last year.
In 2020, Grisham slashed .286/.311/.571 against the fastball. This year, those numbers look like this: .213/.215./.436. All career lows.
In 2019, his first year in the league, he hit .261 against the fastball. It was by far his best pitch to hit, where he batted .200 against breaking pitches and a slightly better off .227 on off-speed stuff. Now, Grisham is batting above .300 on everything but the fastball.
He is almost an unrecognizable hitter, despite batting .269 on the season and slugging .485.
As pitchers have noticed the weakness, they are targeting it. The fastball has been used as a put-away pitch on Grisham 25 percent of the time. That’s up seven percentage points from a truncated season in 2020. He has swung and missed at fastballs 26 percent of the time, also a career high.
Of course, other players on the Padres will also benefit.
Ha-seong Kim, who was signed by the Padres in part to be a power bat, has struggled since coming to the majors catching up with speed. He is batting just .223 against the fastball, near the bottom among Padres.
Victor Caratini, too, will be a likely benefactor.
But both of those players aren’t the stalwart in the lineup that Grisham is, and can be.
Grisham’s presence on last year’s team was worth 2.5 wins above replacement. Offensively alone he was worth 1.9 WAR. Compared to the average batter, according to baseball-reference.com, he was worth seven more runs in 2020.
Without hitting the fastball, though, the numbers have dipped.
A lot of that will have a chance to change in the second half of the season with the pitchers at least not able to blatantly use the spin-enhancing material.
The change will also start for Grisham, poignantly, against the Dodgers, who have been at the heart of the spin rate scandal. The Dodgers pitching staff has seen the second largest increase in spin rate from year to year in the majors. Starting pitcher Trevor Bauer has the highest individual increase.
Grisham, fittingly, has gone 0 of 5 with four strikeouts against Bauer this season.
The Padres will see him Wednesday. Until then, Grisham is hoping to get on track.