Evan Sisk’s fastball and sinker, both of which average around 91 mph, aren’t blowing away opposing batters.
When the Pittsburgh Pirates left-handed reliever brings the heat, he does so well below league average, which, per Statcast, is around 93 mph for both pitches.
But despite not possessing overwhelming speed, Sisk has found success with the Pirates this season, as a unique release point has largely left batters disadvantaged in trying to put a good swing on his offerings.
“From the slot he throws, he’s able to generate movement on his pitches,” manager Don Kelly said. “A lot of hitters don’t see — there’s deception to it and with the movement, I think it makes it difficult to square it up.”
Welcome back Evan Sisk
3 strikeouts in 10 pitches in the bottom of the 9th pic.twitter.com/TNevOwgnOW
— Platinum Key (@PlatinumKey13) April 14, 2026
Among left-handed starters and relievers in MLB, Sisk owns one of the lowest arm angles at the point of release.
A pitcher with an arm angle of zero degrees releases the ball completely horizontally to the flat ground.
By contrast, a submariner like the Blue Jays’ Tyler Rogers owns an arm angle of minus-61 degrees.
Pitchers with over-the-top deliveries, such as the Dodgers’ Tyler Glasnow or Kansas City’s Michael Wacha, have arm angles in the high 50s.
Sisk’s arm angle stands at 23 degrees, making him an extra difficult opponent for left-handed batters, who are hitting just .188 against him entering Tuesday’s contest at St. Louis.
The 29-year-old, originally a 16th round draft pick by the Cardinals in 2018, didn’t always throw that way, but while pitching at College of Charleston, he altered his release point as a way to compensate for not possessing the fastest stuff.
“I started in college throwing a little bit higher in my release slot, but my sophomore year, I dropped down and that was the start of that,” Sisk said. “Immediately, you see some of the takes you get. So I definitely use it to my advantage.
“I know I’m going to be tough on lefties, so I just really want to be in the zone with them. In college, I was throwing probably 86-89 (mph) — didn’t throw the hardest, so I needed some kind of uniqueness or deception. That was the inspiration.”
Sisk’s unique delivery has helped him post a 1.42 ERA through 15 appearances this season after being called up from Triple-A Indianapolis on April 13.
Over 19 innings, he’s struck out 24 with just five walks, recording a WHIP of 1.00 and an opposing batting average of .209.
Entering the Pirates’ series in St. Louis, Sisk has yet to be scored upon in May and has allowed only three earned runs all year.
“I think it just comes down to going in, executing, picking your lane and throwing a pitch where you want to go,” Sisk said. “If you execute, it’s going to give you the best chance for success.”
Complementing Sisk’s fastball and sinker is a curveball he throws about 27% of the time, along with a sweeper and changeup.
Generally speaking, Sisk keeps things off-speed when facing left-handed hitters, who already have to deal with the ball actually being released slightly behind their bodies due to his release point.
“We stick pretty heavily to sinker, sweeper, curveball to lefties and then righties get the full mix — all five pitches,” Sisk said. “I think as long as I can go in and execute the way I want to, it’s going to put me in a good spot for success.”
On top of traditional stats, Sisk’s analytics thus far are strong across the board.
His 31.6% strikeout rate ranks in the 94th percentile in baseball, while his opposing exit velocity (84.7 mph) is in the 96th.
Sisk also boasts an expected batting average of .161.
Sisk’s above-average extension has been an additional factor.
Statcast’s extension metric measures in feet how far in front of the mound rubber, which is 60 feet, 6 inches away from home plate, a pitcher releases the baseball.
Taller pitchers (Sisk is 6-foot-2) and those who can maximize the distance that they stretch away from the rubber before delivering can deny batters critical milliseconds of reaction time before the ball arrives.
In other words, Sisk’s extension of 7.0 means that he’s releasing the ball about 53 feet away from home plate, which can make his pitches appear faster to batters.
“Just hiding the ball as long as I can, really getting out front and releasing the ball close to home plate — hopefully it’ll give me a mile per hour or two (extra),” Sisk said.
To date, Sisk has been deployed mainly in middle relief scenarios, as well as multi-inning situations.
With the Pirates’ bullpen struggling of late and this season overall, Kelly has been pleased with Sisk’s performance.
“He’s doing a great job,” Kelly said. “I think it’s the uniqueness of the delivery — you don’t see too many guys, especially from the left side, throwing like that. And then the stuff, the movement with that delivery, and throwing strikes has been a big key for him. He’s getting ahead of guys and using it effectively against both right-handers and left-handers.”