Potential 2021 Starting Pitcher Strikeout Rate Surgers, A Review

At the end of March, I shared a list of starting pitchers who posted the largest gaps between their Spring K% marks and their Steamer projected K% marks. A many years old study I conducted confirms that Spring strikeout rate does convey meaning, so while 99% of Spring stats should be ignored, strikeout rate isn’t one of them. Small sample sizes and uneven competition caveats still heavily apply, though. Let’s find out how these Spring strikeout rate surgers actually performed. How many, if any, beat their Steamer projected strikeout rates?

Wow, I’m not sure we could have possibly asked for better results than this! Eight of the ten pitchers posted a strikeout rate above their Steamer projected strikeout rate, seven of them beating the projection by at least 2.7%. One of the pitchers that disappointed only recorded 15 innings. This looks like pretty strong evidence of accounting for Spring strikeout rate in your projections.

Trevor Rogers enjoyed the largest gap between his Spring K% and Steamer projected K% and didn’t disappoint. He upped his SwStk% and ended up throwing all three of his pitches (fourseam, changeup, and slider) for double digit marks. Beware luck regression next year though, as he’s not going to post another microscopic 5% HR/FB rate.

Logan Webb was a favorite breakout candidate of mine, thanks to his skills foundation and the Spring strikeout rate surge. Like Rogers, he enjoyed a true breakout season with beautiful skills — a high strikeout rate, low walk rate, and gobs of ground balls. It was his curveball that took off this year, notching a SwStk% just over 20%, to go along with a solid changeup.

Huascar Ynoa was perhaps the type of player this article delivered the most value advice on. I never even heard of the guy and probably wouldn’t have even projected him until I noticed his ridiculous Spring strikeout rate. Injury limited him to just 91 innings, but he posted strong skills en route to a 3.61 SIERA. He was likely pretty close to free in your leagues, so earned a nice profit while on the mound, which could have been more if not for an 18.4% HR/FB rate.

It’s hard to believe there was upside to Corbin Burnes’ 28.2% strikeout rate projection. But he was insane again during the Spring and ended up delivering his second straight strikeout rate above 35%. It’s crazy to remember that this is the same guy who got clobbered in 2019 with a .414 BABIP and 38.6% HR/FB rate.

I can’t fault Steamer for its 30.2% strikeout rate projection for Tyler Glasnow, but a Spring strikeout rate over 40% suggested that maybe, just maybe their forecast was a tad too low. Sure enough, before his season was cut short due to an elbow injury that required TJ surgery, his strikeout rate remained in the mid-30% range, buoyed by a career best 17.2% SwStk%. It’s too bad he had to go under the knife, as it’s anyone’s guess how he’ll be when fully recovered.

Sandy Alcantara throws in the high 90s, so he’s one of several pitchers you always assume is capable of striking out more batters. His Spring surge suggested that 2021 may finally be the time. It wasn’t exactly, as while his strikeout rate did rise, it merely jumped to just 24%, but it was enough to handily beat Steamer’s projection which had actually forecasted a decline from 2020. Encouragingly, his SwStk% spiked to a career best 13.3%, but he still struggles to get called strikes, which is limiting his strikeout rate potential now.

I think given his prospect pedigree and age, most would have taken the over on Steamer’s projected strikeout rate for Casey Mize. Surprisingly, he barely beat it, but was likely profitable for his owners anyway thanks to some hefty BABIP and LOB% luck. The problem right now is that while his fastball has been above average at inducing whiffs, he doesn’t have any secondary out pitches to rack up the strikeouts. Both his slider and splitter sit with SwStk% barely into double digits, and that’s just not exciting. Both pitches earned his scouting grades, so you would think the potential is there to improve them to generate more swings and misses. But we won’t know until it actually happens.

There was an exciting battle for the fifth starter slot in Oakland during the Spring between two top prospects in Daulton Jefferies and A.J. Puk, along with the less familiar Cole Irvin. I figured whoever won the job would make for an excellent late round/cheap target. Irvin ended up winning the job and was certainly respectable, but relied on lots of luck to deliver any sort of deep league value, as he handily outperformed his unappealing SIERA. Irvin’s strong Spring strikeout rate failed to carry over to the regular season. Meanwhile, Jefferies battled injuries was recorded just 92 innings between Triple-A and MLB, as his strikeout rate tumbled at both spots, perhaps due to a lack of complete health.

Finally, Steamer projected former top prospect Brady Singer to suffer a strikeout rate decline off his 2020 debut, and while Singer’s mark did drop, it was much less severe than forecasted. It didn’t really matter for fantasy owners though as despite posting a near-identical SIERA, his ERA shot up to near 5.00 thanks to a ridiculous .350 BABIP and suppressed LOB%. He doesn’t exactly excite me, but he should clearly post better results in 2022 and deliver positive value in AL-Only and deep mixed leagues.