The angle he throws from is unusual, and hitters notice
Kelly releases the ball from a sidearm slot, about 17 degrees above horizontal and 3.0 feet to the third-base side of the rubber.
275 tracked release points, averaging 5.3 feet off the ground.
When he falls behind, hitters know exactly what is coming
Behind in the count Kelly throws a fastball 91.3% of the time, against 49.2% when he is ahead.
92 pitches behind in the count, 65 ahead.
One type of hitter does all the damage against him
Hitters do their damage on his fastballs: a .418 expected average against them, against .212 on his breaking balls.
206 of his fastballs thrown.
One pitch of his runs sideways more than almost anyone's
Kelly's sweeper moves 18.2 inches toward the first-base side, the biggest horizontal move in his arsenal.
59 thrown, averaging 81.6 mph.
This is the pitch he goes to when he needs the out
With two strikes Kelly goes to the 4-seam fastball: 28.7% of his two-strike pitches, against 7.7% the rest of the time.
80 two-strike pitches in 2026.
His fastball is the pitch everything else is built on
Kelly's cutter averages 90.6 mph, and has touched 93.6.
121 thrown, 44% of his pitches.
He falls behind hitters far too often
Kelly throws a strike on the first pitch 47.1% of the time.
68 plate appearances started in 2026.
The gap between his pitches is what makes them work
14.3 mph separates Kelly's sinker from his sweeper, 96.0 against 81.6.
47 and 59 of them respectively.
He gets so far down the mound the ball arrives early
Kelly releases the ball 7.1 feet down the mound, so the ball arrives sooner than the radar gun suggests.
221 tracked pitches in 2026.
He pitches around the zone once runners are on
Kelly throws 46.3% of his pitches in the zone with a runner in scoring position and 40.6% with the bases empty.
95 pitches with a runner in scoring position, 180 with the bases empty.
The contact he allows is the kind that finds grass
The quality of contact against Kelly projects a .372 average, 12th percentile.
275 pitches in 2026. 12th percentile among qualified pitchers in 2026, 472nd in MLB.
He works one part of the zone far more than the rest
Kelly lives at the bottom of the zone: his average pitch crosses at 2.27 feet, against a zone that runs 1.5 to 3.5.
275 located pitches in 2026.
He saves one pitch for one side of the plate
Kelly throws the 4-seam fastball 27.8% of the time against left-handers and 7% against right-handers.
185 pitches to right-handers, 90 to left-handers.
His ball moves more than the hitter expects it to
Kelly's stuff spins at 2,401 rpm, 76th percentile in the league.
275 pitches in 2026. 76th percentile among qualified pitchers in 2026, 129th in MLB.
He throws strikes to one type of hitter and not the other
Kelly lands 47.1% of his fastballs in the zone and only 32.2% of his breaking balls.
206 of his fastballs, 59 of his breaking balls.
His pitches move in ways that fit together
Kelly works with 4 pitches: Cutter, Sweeper, Sinker and 4-Seam Fastball. The cutter is 44% of everything he throws.
275 classified pitches in 2026.
One pitch of his moves in a way hitters rarely see
Kelly's sinker carries 10.4 inches of ride against a spinless ball, the biggest vertical move in his arsenal.
47 thrown, averaging 96.0 mph.
Hitters cannot square him up, the contact is weak
Contact against Kelly is weak: 86.8 mph off the bat on average, 74th percentile.
275 pitches in 2026. 74th percentile among qualified pitchers in 2026, 143rd in MLB.
One pitch of his spins more than almost anyone's
Kelly's sweeper spins at 2,613 rpm, the highest in his arsenal.
59 thrown in 2026.
How much of the zone he uses depends on the count
Kelly puts 57.6% of his pitches in the zone when he is behind and 43.1% when he is ahead.
92 located pitches behind, 65 ahead.
He lives on the edges rather than over the middle
17.8% of Kelly's pitches land in the middle third of the zone, well below what most pitchers give away.
49 of 275 located pitches.
There is one pitch of his that keeps getting hit
Contact off Kelly's cutter leaves the bat at 88.7 mph, against 86.5 off his sinker.
121 and 47 of them thrown.
One pitch exists only to make the hitter think
Kelly has thrown 10 changeups this season, 3.6% of his pitches, at 83.6 mph: a look rather than a weapon.
275 classified pitches in 2026.
Show more
The numbers behind these live in Pitch Data.
Take me there
The angle he throws from is unusual, and hitters notice
Kelly releases the ball from a sidearm slot, about 17 degrees above horizontal and 3.0 feet to the third-base side of the rubber.
275 tracked release points, averaging 5.3 feet off the ground.
He gets so far down the mound the ball arrives early
Kelly releases the ball 7.1 feet down the mound, so the ball arrives sooner than the radar gun suggests.
221 tracked pitches in 2026.
The numbers behind these live in Pitch Data.
Take me there
When he falls behind, hitters know exactly what is coming
Behind in the count Kelly throws a fastball 91.3% of the time, against 49.2% when he is ahead.
92 pitches behind in the count, 65 ahead.
This is the pitch he goes to when he needs the out
With two strikes Kelly goes to the 4-seam fastball: 28.7% of his two-strike pitches, against 7.7% the rest of the time.
80 two-strike pitches in 2026.
He falls behind hitters far too often
Kelly throws a strike on the first pitch 47.1% of the time.
68 plate appearances started in 2026.
How much of the zone he uses depends on the count
Kelly puts 57.6% of his pitches in the zone when he is behind and 43.1% when he is ahead.
92 located pitches behind, 65 ahead.
The numbers behind these live in Pitch Data.
Take me there
One type of hitter does all the damage against him
Hitters do their damage on his fastballs: a .418 expected average against them, against .212 on his breaking balls.
206 of his fastballs thrown.
He throws strikes to one type of hitter and not the other
Kelly lands 47.1% of his fastballs in the zone and only 32.2% of his breaking balls.
206 of his fastballs, 59 of his breaking balls.
The numbers behind these live in Pitch Data.
Take me there
One pitch of his runs sideways more than almost anyone's
Kelly's sweeper moves 18.2 inches toward the first-base side, the biggest horizontal move in his arsenal.
59 thrown, averaging 81.6 mph.
One pitch of his moves in a way hitters rarely see
Kelly's sinker carries 10.4 inches of ride against a spinless ball, the biggest vertical move in his arsenal.
47 thrown, averaging 96.0 mph.
The numbers behind these live in Pitch Data.
Take me there
His fastball is the pitch everything else is built on
Kelly's cutter averages 90.6 mph, and has touched 93.6.
121 thrown, 44% of his pitches.
The gap between his pitches is what makes them work
14.3 mph separates Kelly's sinker from his sweeper, 96.0 against 81.6.
47 and 59 of them respectively.
He saves one pitch for one side of the plate
Kelly throws the 4-seam fastball 27.8% of the time against left-handers and 7% against right-handers.
185 pitches to right-handers, 90 to left-handers.
His pitches move in ways that fit together
Kelly works with 4 pitches: Cutter, Sweeper, Sinker and 4-Seam Fastball. The cutter is 44% of everything he throws.
275 classified pitches in 2026.
One pitch of his spins more than almost anyone's
Kelly's sweeper spins at 2,613 rpm, the highest in his arsenal.
59 thrown in 2026.
There is one pitch of his that keeps getting hit
Contact off Kelly's cutter leaves the bat at 88.7 mph, against 86.5 off his sinker.
121 and 47 of them thrown.
One pitch exists only to make the hitter think
Kelly has thrown 10 changeups this season, 3.6% of his pitches, at 83.6 mph: a look rather than a weapon.
275 classified pitches in 2026.
Show more
The numbers behind these live in Matchups.
Take me there
He pitches around the zone once runners are on
Kelly throws 46.3% of his pitches in the zone with a runner in scoring position and 40.6% with the bases empty.
95 pitches with a runner in scoring position, 180 with the bases empty.
The numbers behind these live in Spray Chart.
Take me there
The contact he allows is the kind that finds grass
The quality of contact against Kelly projects a .372 average, 12th percentile.
275 pitches in 2026. 12th percentile among qualified pitchers in 2026, 472nd in MLB.
Hitters cannot square him up, the contact is weak
Contact against Kelly is weak: 86.8 mph off the bat on average, 74th percentile.
275 pitches in 2026. 74th percentile among qualified pitchers in 2026, 143rd in MLB.
The numbers behind these live in Pitch Data.
Take me there
He works one part of the zone far more than the rest
Kelly lives at the bottom of the zone: his average pitch crosses at 2.27 feet, against a zone that runs 1.5 to 3.5.
275 located pitches in 2026.
He lives on the edges rather than over the middle
17.8% of Kelly's pitches land in the middle third of the zone, well below what most pitchers give away.
49 of 275 located pitches.
The numbers behind these live in Pitch Data.
Take me there
His ball moves more than the hitter expects it to
Kelly's stuff spins at 2,401 rpm, 76th percentile in the league.
275 pitches in 2026. 76th percentile among qualified pitchers in 2026, 129th in MLB.
Red Sox
Career team 2022–2026