Article: Chris Bassitt Is Walking Tall – By Not Walking Anyone at All

[Leo Morgenstern]

Following a hot start to the season, Chris Bassitt is looking more like his old self.

We knew that the version of Bassitt with a sub-1.00 ERA was never going to stick around all year. He has more than quadrupled his ERA over his last four starts, bringing it up from 0.77 on April 16 to 3.35 after his latest start on May 8. Still, he has pitched into the sixth in each of his last four outings and has not given up more than four earned runs in a start. Bulk and reliability are exactly what the Blue Jays need from Bassitt; his strong showing in his first four starts was just a cherry on top.

Yet, while Bassitt has regressed, the flame from his hot start hasn’t been altogether extinguished. There is one thing he continues to do exceptionally well. Bassitt walked five of 93 batters through his first four games, good for a 5.4% walk rate. If he had kept that up all season, it would have been the best of his career. But he hasn’t kept it up; he’s brought it down.

Across his last four starts, he has walked only three of 103 batters (2.9%), bringing his walk rate on the season down to 4.1%. Entering this year, his career walk rate was 7.6%. His lowest walk rate in any season was 6.1% (in 2021). As recently as 2024, his walk rate was as high as 9.2%. At risk of sounding like your grade school math teacher, 4.1% is a lot lower than all of those other numbers. 

Chris Bassitt's Walk Rate by Year

Season	IP	BB%
2014	29.2	9.5%
2015	86.0	8.3%
2016	28.0	10.5%
2018	47.2	9.3%
2019	144.0	7.7%
2020	63.0	6.5%
2021	157.1	6.1%
2022	181.2	6.6%
2023	200.0	7.1%
2024	171.0	9.2%
2025	45.2	4.1%

Bassitt’s 25% strikeout rate right now would also be a career high, just edging out his 24.96% rate from 2021. However, his strikeouts have dropped off considerably as of late – he struck out 33.3% in his first four starts and just 17.5% in his last four – so I’m not inclined to believe that he’ll maintain that career-best strikeout rate much longer. His walk rate is far more interesting. 

I should emphasize that his low walk rate could still be an effect of small sample size (SSS) randomness. After all, Bassitt has had short stretches with similarly low walk rates before. His walk rate hasn’t been quite this low in any eight-game stretch since his All-Star 2021 season, but he did have an eight-start stretch as recently as 2023 with a 4.9% walk rate. He also had several eight-game stretches with a walk rate below 5.0% in 2022. 

Eight-Star Stretches of Bassitt's Career With a Walk Rate Under 5%

Span Start	Span End	BB%
Apr 24, 2021	Jun 1, 2021	3.4%
Apr 29, 2021	Jun 8, 2021	3.4%
Apr 18, 2021	May 27, 2021	3.8%
Jun 30, 2015	Aug 15, 2015	4.1%
Mar 30, 2025	May 8, 2025	4.1%
Jul 24, 2019	Sep 7, 2019	4.1%
May 5, 2021	Jun 13, 2021	4.4%
Jul 6, 2021	Aug 17, 2021	4.5%
Jun 3, 2022	Jul 23, 2022	4.5%
Jun 30, 2021	Aug 12, 2021	4.6%
Jun 19, 2022	Aug 8, 2022	4.7%
Jul 8, 2022	Aug 19, 2022	4.7%
Jun 25, 2022	Aug 14, 2022	4.8%
Jul 30, 2019	Sep 13, 2019	4.8%
Jul 11, 2021	Sep 23, 2021	4.8%
Jun 14, 2022	Aug 3, 2022	4.9%
Jul 5, 2015	Aug 21, 2015	4.9%
May 12, 2023	Jun 18, 2023	4.9%
Jun 24, 2021	Aug 6, 2021	4.9%

That being said, the last time Bassitt started a season with a walk rate this low over his first eight starts was his rookie campaign in 2015. (Funnily enough, he faced exactly 196 batters and walked exactly eight through his first eight starts in both years.) That season, however, he didn’t make his first start until the end of June, and he only made 13 starts in total. So, this is the first time we have ever seen Bassitt jump out of the gate with such a low walk in April and May. SSS weirdness is inevitably more intriguing at the beginning of a season, because we can always imagine it will last all year.

Furthermore, Bassitt crossed the rule-of-thumb stabilization threshold for walk rate (170 batters faced) in his last start. That doesn’t erase SSS concerns, but it means, at the very least, that he has now faced enough batters (and walked so few of them) that it’s worth taking a closer look at what he might be doing differently.

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The most obvious explanation for a decrease in walk rate is an increase in zone rate – in other words, an increase in pitches thrown within the bounds of the strike zone. But that’s not what’s going on here. Bassitt’s zone rate in 2025 is 51.2%. That’s higher than his 50.1% zone rate in 2024, but it’s still lower than his 52.5% career average. So, he’s not throwing more strikes. Nevertheless, he’s earning more strikes because he's inducing swings at a rate like never before. 

Over the first 10 years of his career, Bassitt’s opponents swung at 46.3% of his pitches. He had never induced a swing rate higher than 47.7% (in 2022). All of a sudden, in 2025, his opponents have offered at more than half of his pitches (50.2%). That means you’d have better luck betting on a coin flip than you would betting that an opposing batter won't swing at a pitch from Bassitt. 

Are you ready to be impressed? Here is a complete list of pitchers (min. 750 pitches) with a swing rate above 50% this season, as of Sunday. Needless to say, a high swing rate is what a pitcher wants:

Pitcher	Zone Rate
Zack Wheeler	50.5%
Chris Sale	50.5%
Chris Bassitt	50.2%
Paul Skenes	50.1%
Garrett Crochet	50.0%

Bassitt has induced swings at career-best rates both inside and outside of the strike zone. However, the number that truly stands out – and the one that matters most for limiting walks – is his out-of-zone swing rate, also known as chase rate. His career chase rate from 2014-24 was 26.0%. His previous career-high chase rate was 27.2%. 

So far in 2025, Bassitt is inducing chase at a 32.1% rate. 

Let me be clear: That’s hardly an elite chase rate. It only puts Bassitt in the 81st percentile of pitchers, according to Baseball Savant. Yet, considering he has never previously ranked above the 43rd percentile, we’re talking about a massive improvement. It’s no wonder Bassitt hasn’t been walking batters; his opponents are swinging at almost a third of his pitches outside of the zone.

So, this isn’t a matter of a wild pitcher reining himself in. It’s not a question of improved control. Rather, it’s all about heightened deception. To that point, the biggest difference in Bassitt's approach this season isn’t where he’s locating his pitches outside the strike zone but where he’s locating his pitches inside the strike zone.

Over the first 10 seasons of his career, Bassitt threw 29.4% of his pitches, and 56.1% of his in-zone pitches, in the area Baseball Savant describes as the heart of the zone. So far in 2025, he has only thrown 25% of his pitches and 48.7% of his in-zone pitches over the heart of the plate. Both of those rates are substantially lower than they’ve ever been. Accordingly, Bassitt has thrown a career-high percentage of his pitches (and his in-zone pitches) on the edges of the strike zone instead. 

Take a look at these two heat maps from Bassitt's player page on FanGraphs. The first shows every pitch Bassitt threw from 2014-24. The second shows every pitch he's thrown so far in 2025. Most of the time, I'd advise against looking at such all-encompassing heat maps, but I was struck by how clear a picture these two paint. Bassitt is avoiding the heart of the zone in a way he never has before: 

You'll see something similar if you compare the Baseball Savant heat maps for each of his individual pitches in 2024 and 2025. This first set of heat maps is from last year:

And this second set is from the current season:

In particular, Bassitt has been throwing more pitches at the sides of the strike zone. There's a good chance this has something to do with his new positioning further to the third base side of the rubber, a change he adopted late last August. Combine his new positioning with the fact that he is a tall, right-hander whose average arm angle has decreased in each of the past two years, and the result is one of the most extreme third base side horizontal release points among all starting pitchers. His unusual release point is surely another piece of the puzzle that has helped him to keep hitters guessing on a horizontal plane.

So, while Bassitt is throwing roughly the same amount of in-zone pitches as he always has, he’s throwing significantly fewer obvious in-zone strikes. I think that's one of the main reasons why his opponents have had so much more trouble differentiating between the pitches they should swing at and the ones they should avoid. 

Even better, Bassitt isn’t only fooling his opponents around the edges of the strike zone. In fact, swings just outside the strike zone (i.e. swings in the out-of-zone portion of the shadow zone) make up a lower percentage of his total chases than in any previous year. By painting the edges, Bassitt seems to have increased the radius of the strike zone for his opponents, thereby tricking them into swinging at more pitches in the chase and waste zones as well. That is all the more impressive in a season in which umpires are calling a much tighter strike zone overall.

Even at his best, Chris Bassitt was never a pitcher who overpowered his opponents. He was never a guy who could challenge batters over the heart of the plate, nor was he a guy who picked up enough strikeouts that he could afford to issue a ton of walks. Now 36 years old, Bassitt is losing velocity – and he never had all that much to begin with. Simply remaining as effective as he was in his first two years with Toronto will be a tall task. In order to pull it off, he needs to rely on command and deception more than ever. There's a lot of season left to play, but so far, he's doing exactly what he needs to do. 

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[Brock Beauchamp]

Excellent article, Leo! I didn't realize Bassitt was getting so many more chases, which gives a little hope his early-season hot start has some sticking power.