Giants fans got used to cheering on a pitcher who relied so heavily on his slider that it legitimately stunned the baseball world and a Hall of Fame hitter when he turned to a fastball to end a World Series. But when Sergio Romo pitched for the Minnesota Twins last year, he wasn't even the right-hander in the bullpen who most heavily leaned on his slider.
That distinction belonged to Matt Wisler, who was surprisingly non-tendered by the Twins earlier this offseason and quickly scooped up by Romo's old team.
Wisler threw his slider an astounding 83.4 percent of the time last season, which was 12 percent more than any big leaguer who threw at least 100 pitches. Romo threw his slider 64.8 percent of the time, the highest rate of his career, and still fell well short of Wisler's usage.
The new Giant is truly an outlier, but as manager Gabe Kapler watched clips of Wisler's outings earlier this month, he had a funny thought.
"I don't know in what world you could say 'bump your usage from 83 percent' but there were actually times when I think, just going back and watching the video, where I might have said throw one more slider there," Kapler said. "Because it's just been a really effective pitch for him."
Wisler only throws the slider and a four-seamer that averages about 92 mph, but that's all he needs. He essentially told big league hitters what was coming in 2020, and still they had no chance. Wisler threw 378 sliders and held opposing hitters to a .143 average and .221 slugging percentage. On August 7, he hung one right in the heart of the strike zone at 79 mph and Kansas City's Ryan McBroom crushed it to center, but no other big leaguer took Wisler deep on a slider in 2020.
The numbers from 2019 are not quite as dominant, but still impressive. Wisler threw his slider 70.5 percent of the time and held hitters to a .206 average with four homers. "Quite simply, it just doesn't get hit all that much," Kapler said when asked about Wisler's slider usage.
The curious thing about Wisler's slider is that it actually only ranked 111th in spin rate, but the pitch rated well above average in vertical and horizontal break, and Wisler was able to keep it in the zone without getting hit hard. He was in the 91st percentile among MLB pitchers in hard-hit percentage and 92nd percentage in whiff rate. That profile should have Wisler pitching important innings for Kapler.
"It's nice to have a guy like that in your bullpen, a strike-thrower and in particular a strike-thrower with a secondary pitch," Kapler said. "You may have noticed that we didn't really have those guys, outside of Tony Watson who could pretty much execute his changeup for a strike whenever he wanted. The rest of our guys, they're not secondary-weapon strike-throwers.
"Even Tyler Rogers, who I consider a very trusted option, a guy who I believe is a strike-thrower, a guy that I think going forward is not going to walk very many guys, it's difficult to control that breaking ball from that (arm) slot. I just think that's an advantage that Matt Wisler has on a lot of bullpen arms out there."