Last 30 Day Strikeout Rate Surprises Since Jun 24 2019

We think we know that pitcher skills change more frequently than hitter skills do, so it pays to monitor pitchers whose skills have spiked over a relatively small sample, like the past 30 days. That’s typically around five starts and a significant change in skills could signal a new talent level. Since the pitcher’s overall season line still includes a lot of the previous skills baked in, fantasy owners might not realize the transformation that has been occurring. So let’s take a look at some of the surprise names that appear near the top of the leaderboard.

Although his season ERA doesn’t show it, Matthew Boyd is enjoying an ultimate breakout season. He has swapped some sinkers for his four-seamer and upped the usage of his slider at the expense of his curve. All of this has made him essentially a two-pitch pitcher. In fact, his repertoire is similar to fellow southpaw Patrick Corbin, except Boyd rarely uses his slider, whereas Corbin uses it more often than his four-seamer. These are good changes, at least for his strikeout rate. Amazingly, all four of his most used pitches have generated double digit SwStk% marks.

He’s taken it up a notch over the last 30 days though, as he has pushed up his slider usage to just above 40%. He’s really testing the limits of his elbow! I can’t tell you how sustainable throwing sliders this frequently are, but it’s been massively effective, so the strikeout rate doesn’t seem like a fluke, though you can’t expect it to remain this high.

Yup, pitchers love moving from the AL to the NL and Sonny Gray is no exception. Many will spout the leaving the big lights of NY as the narrative, but it’s a combination of the league switch and better batted ball and strand rate luck. His SIERA hasn’t changed a whole lot since 2014. This year, Gray has reduced his reliance on his sinker, upping his usage of his four-seamer and slider. Again, good for strikeouts. The difference in the last 30 days is a surge in curveball usage. It hasn’t exactly been great at inducing whiffs, but it’s surely been better than his fastballs and changeup that he replaced with the pitch. Though he might not want to for health reasons, he would probably be even better off relying more on his slider, since that has always been his best pitch for whiffs.

Asher Wojciechowski who?! These last 30 days have been the only days he has pitched in the Majors this year, so we have nothing to compare his pitch selection to. Wojciechowski turned heads in his last start when he struck out 10 Red Sox hitters in 7.1 innings. The guy is already 30 years old, so isn’t a prospect and has just 101.2 MLB innings to his name going back to 2015. This year he has swapped his changeup and four-seamer for a cutter and the new pitch has been ridiculous, generating a 25% SwStk%. In fact, all his pitches are in double digits in the metric. It wasn’t until 2017 that he has shown any sort of strikeout potential in the minors (he has pitched there since 2010), so it’s hard to take this seriously. But he’s been legit awesome so far.

Lance Lynn has been on quite the run, and it’s bizarre that this strikeout rate spike is happening now in hitter friendly Texas. His fastball velocity has spiked to a career high and he has swapped out sinkers for four-seamers and cutters. That has led to a career high fly ball rate, but he’ll take it if the reward is a strikeout rate surge. His last 30 day pitch mix hasn’t changed much except for more four-seamers at the expense of all his non-cutter pitches. Since his best pitch only generates a low teen SwStk% and he’s clearly relying on that added velocity, I’m less optimistic he could sustain this newfound level of skills in the future.

Shane Bieber has actually posted a strong strikeout rate all year and the last 30 days actually represents a decline from the previous period. But I included him here because a mark above 30% is a surprise to begin with. He has upped the usage of all his pitches at the expense of his four-seamer, and man, that slider and curveball have been gooooooood. Both pitches have recorded SwStk% above 20%! It’s too bad that his fastball stinks.

Anthony DeSclafani is exactly the kind of name I was hoping this exercise would uncover. His overall season line is mediocre and not strong enough to tempt shallow mixed league owners. But, his fastball velocity is way up and he has really changed his pitch mix versus previous seasons. For the year, he is throwing his four-seamer more instead of his sinker, and his curve more at the expense of his slider. Over the last 30 days, his mix has remained about the same, while his velocity has taken another step up. That extra oomph has resulted in a career best SwStk% mark for his four-seamer. His fly ball tendency makes him scary to own and prone to horror starts with multiple homers allowed, but he should be an asset in mixed leagues for as long as that velocity stays up.