What Has Led to Kyle Harrison’s Breakout Season?

The Milwaukee Brewers' pitching lab strikes again. Stop me if you’ve heard that one before. Mere months after they traded for Kyle Harrison in a deal that involved Caleb Durbin and the rest of this team’s former third base depth chart, they've watched the young left-hander emerge as a vital part of their starting rotation. Today, we’ll explain what Harrison is doing so well. 

Building The Background
While he’s relatively young (just 24 years old), the Brewers are Harrison’s third MLB team already. He started his major-league career with the San Francisco Giants, who picked him in the 3rd round in 2020, went to the Red Sox last June in the Rafael Devers trade, and then was flipped to Milwaukee just months later. So far in his career, he’s been solid, but there are a few metrics that Harrison has improved in that have led to what could be a career year in 2026. Let’s dive in.

Getting Players To Chase
First, the strikeout rate. Harrison is striking out 29.2% of the hitters he faces. In four years, the lefty’s previous career high was 24.4%, set just last year. 

Right there with it, his chase rate and whiff rate are in the top quartile of the league, with a very impressive K-per-9 mark for a starting pitcher. What could be leading to this spike in strikeouts? Harrison’s out-of-zone pitch percentage has actually gone up a couple of ticks, but the opposing swing rate is up, and his out-of-zone swing percentage is up. This means now, more than ever, the southpaw is throwing pitches that look appetizing off the hand but end up being not-so-great decisions for the opposing hitter. 

Jumping Ahead In The Count
Another metric that has led to higher strikeout percentages (and more success, overall) is a simple one, but it’s one that the Brewers pitchers are great at hammering home. His first-pitch strike percentage is at 70, which is 9.4 percentage points better than last year. 

The dance that pitchers and hitters do is mainly dictated by count leverage, and if you’re up 0-1 70% of the time, it usually spells advantage to the pitcher. Harrison simply has command of his pitches more than ever, and once he’s able to get that leverage, hitters get into defensive mode and have to try and fight off anything close.

Minimizing Hard Hit Rate
Another metric to keep an eye on is hard-hit rate, because even the best pitchers are going to give up contact, and Harrison passes the eye test there, too. The former Giant is allowing a hard-hit ball just 30.1% of the time, putting him in the top 12% among all big-league pitchers. His offspeed stuff is much nastier in the past, thanks to a new grip on the changeup, a new position on the rubber, and a change to his arm angle.

The bottom line is this: the Brewers have done it again. We’re starting to see some of the dividends with Brandon Sproat as well, but the left-handed Harrison already looks like he's living up to the prospect hype he garnered just a few short years ago.