Tracking Four-Seam Velocity: The Risers

In the heat of summer, it is always interesting to track pitchers who have gained velocity and who are losing velocity, and what the impact is on their results. While velocity alone does not guarantee success, meaningful changes often coincide with adjustments in command, pitch quality, or overall effectiveness. Identifying those trends mid-season can be a very useful indicator to see if a pitcher could strengthen as the season goes on or decline. This piece will look at those hopefully strengthening in the summer.

Sean Burke, Chicago White Sox

Outside of Misiorowski ludicrously increasing his average velocity by almost 2.5 mph to sit at 102, the next name on this list is Sean Burke of the White Sox. This season has not been plain sailing, both in terms of his velocity, as the graph might suggest, or with his results, which have also been somewhat inconsistent. He has struggled with command, issuing walks, especially as he has picked up some fastball velocity. That has been the clearest sign of that inconsistency. His rolling walk rate sat around 5% through April and May, then climbed sharply once the velocity gain took hold in mid-June, peaking near 9% in early July. It has come down some since, but as of his most recent starts it’s still sitting around 7-7.5%.

July has still been his best month by results. He really struggled in May and has been recovering since. After sitting  93.6-93.8 mph on his fastball in April, he was able to increase that to the upper 94s, but with pretty bad results; certainly from a fantasy perspective, he would not have been rosterable.

Then, from mid-June, after not averaging 96 mph in a single start all season, he made another leap and has sat 96 mph in four of his last six games, and below 95 in just one of them.

Across these six starts, the results line up cleanly with velocity. In the four outings where he sat around 96 mph (June 18, June 29, July 4, July 10), opponents managed an average .185 xwOBA against the fastball, with a 35.2% whiff rate and a 35.5% put-away rate. In the two starts where he dropped to 94.7-95.4 (June 23, July 19), xwOBA against roughly doubled to .377, whiffs fell to 21.6%, and the put-away rate dropped by more than half to 15.4%.

Worth a caveat given how small these samples are; each start is only 6-14 fastballs against, so a single well-struck ball or a couple of extra whiffs can swing the per-start numbers a lot. But the direction is consistent across every single one of the six starts, and if the walk rate keeps trending down from its early-July peak, this could be the version of Burke we hopefully get for the rest of 2026.

Roki Sasaki, Los Angeles Dodgers

The enigma that Roki Sasaki has been through his major league career continues. Seemingly, month-to-month, going from a Triple-A level arm to an All-Star, he has already gone through multiple phases in this short season. The introduction of a dual-split — regular splitter and forkball — helped him massively to gain command and the ability to be able to trust himself to throw strikes. Since then, he has slowly worked his way back to his ceiling of triple digits that made him the prospect he was coming out of the NPB.

From May 30th onward, Sasaki has crossed 98 mph in 7 of his last 9 starts, a level he touched only occasionally before that (his four-seamer sat mostly in the 96.3-97.8 range through late May). Splitting his full season at that 98 mph line:

In the 7 starts at 98.0+ mph: average xwOBA against .326, 22.0% whiff rate, 19.5% put-away rate.

In the 11 starts below 98.0 mph: average xwOBA against .465, 17.9% whiff rate, 12.8% put-away rate.

But to pair with this increased velocity has come more control. The walk rate is steadily decreasing even if the line is exaggerated by that start in April; it has settled into a consistent decline.

An important secondary observation from the chart is not just the walk rate, but also how much more regularly he tops out at 100 mph. To me, this indicates confidence in his pitching and trust in his ability. For a pitcher who has shown mental vulnerability in his young career, this can only be a great sign moving forward. This, paired with some of his highest spin rates of the season, topping 2400 in his last start for the first time this season, pushes his floor a lot higher for the back part of the season, for a pitcher whose ceiling is already sky high.

Gavin Williams, Cleveland Guardians

Less is more has become Gavin Williams’ mantra in 2026. By scaling back his four-seamer, he has unlocked an even better version of the pitch before accounting for the added velocity. Usage dropped from 37.4% of his total pitches in 2025 to 23.9% in 2026, a big shift in pitch mix. With the increase again in his sweeper usage introduced in 2025, he now has three plus pitches to go along with his sinker. His fastball’s run value has gone from −0.8 per 100 pitches in 2025 to +0.6 this year, taking it from a below-average pitch to a genuinely above-average one, and the raw run value has flipped from −8 runs to +3. Opponents managed a .383 wOBA against the pitch last year; this year that’s down to .262, with expected wOBA telling the same story, .384 down to .305. The bat-missing has jumped too. Whiff rate is up from 23.3% to 29.5%, and the strikeout rate on the pitch has nearly doubled, from 18.6% to 36.3%.

If we zoom into 2026 specifically, this improvement is to his fastball. Every start from May 10th onward has sat at 96.3 or higher, no exceptions. And March/April never touched 98 even once; his ceiling that whole stretch was 97.5. From June 8th on, he’s hit 98+ in five of nine starts, a velocity ceiling that didn’t exist in his first six weeks of the season.

Again, over a small sample, but in July, when his velocity has climbed to its highest, it has performed its best, striking out a remarkable 11 hitters in his last three games, with nine punchouts coming on his four-seamer in his start against Pittsburgh.

Gavin Williams has always been a really intriguing pitcher, with great bat-missing potential but has always struggled with walks and command. This season, he has seemed to have turned a corner, as in 2026, he is issuing the fewest walks in his career (7.3%), as well as striking out more batters than in previous seasons. If he can maintain this velocity, it only increases his floor while keeping the ceiling just as high.

Chris Sale, Atlanta Braves

The fact that Chris Sale, at age 36, is featuring in a biggest velocity gainers piece at the end of July is pretty remarkable. Coming off an injury-shortened 2025 season, he has so far put up his best ERA since 2018, and another well-deserved All-Star appearance. Even up from last season’s average, where his four-seamer averaged 94.8 mph, his season average for 2026 is now at 96.1, but recently it has been much closer to 97.

The growth is exaggerated by a 92 mph average outing at the beginning of April, which brings his first month down, obviously. Nonetheless, he has climbed steadily to as high as 97.5 mph in an outing against the White Sox and has since averaged in the upper 96s.

When you have had the career that Chris Sale has had, there is not much more that can be said, but his value as one of the elite fantasy arms is still on display, and if his four-seam velocity is anything to go by, this is not letting up, and he has plenty of gas still left in the tank. At 36, most pitchers are managing their velocity down, not building it back up. Sale hasn’t followed that script, and as long as the fastball keeps sitting in the upper 90s, there’s little reason to expect his strikeout upside or fantasy value to slip.

But his ability to go as high as 99 mph pretty much when he feels angry enough is reassuring for all.