Surging Swinging Strike Rates by Paul Sporer April 21, 2021 I wanted to dive in on the guys with the biggest swinging strike rate (SwStr%) gains in the early going (min. 10 IP). Where are they getting these new whiffs from, is the surge sustainable, and has it changed their fantasy outlook substantially? Alex Cobb, LAA | +9 pts to 19% Cobb’s fast start is tied directly to the return of his splitter aka The Thing. The 1.5 Pitch Value makes it the third best splitter in the league thus far (by results, Pitch Value doesn’t guarantee future success), behind only Kevin Gausman (4.1) and Aaron Civale (2.1). He showed some flashes of getting back on track last year, particularly with the splitter which earned a 2.6 Pitch Value. Scaling those figures on a per 100 basis, it’s up from 0.9 PV/100 to 1.8 PV/100. He is using the pitch more than ever at a 45% clip and the jump in whiffs has fueled career bests in K% (35%) and SwStr% (19%). It is just two starts, but Cobb has put himself back on the radar as at least a team streamer (someone you move back and forth from your lineup to your reserve roster, as opposed to a standard streamer who you cut after using). Dustin May, LAD | +6 to 14% I had concerns about May coming into the season because he lacked the swing-and-miss necessary to generate a strikeout rate commensurate with his draft price. Enter his cutter. After generating a 14% SwStr% in 2019-20, it has soared to 26% and helped him log strikeout totals of 8, 6, and 8 in his first three starts totaling 15.3 innings. Cutters have averaged a 13% SwStr% since 2019 so he is trending well above average and actually slots 2nd to only Jakob Junis among the 59 pitchers with at least 40 thrown. His curveball is also up 5 points to an 18% SwStr% and he is using it at a career-high 20% clip. With two above average whiff offerings, May is showing early signs of a major leap forward. He is still getting a ton of groundballs with his nasty sinker, too, giving all of the elements of a potential fantasy ace. Adbert Alzolay, CHC | +6 to 14% If you look at Alzolay’s page, you will see an 11% SwStr%, but this 6-point surge compares his rates as a starter. His fastballs are driving the improvement. He throws a distinct four-seamer and sinker, each used at least 24% of the time. After a 7% combined SwStr% with them last year, he is up to 12% so far this year. The slider remains his go-to whiff offering with a 23% SwStr% both this year and last and his usage is up 13 points to 38%. Alzolay was sent to the alternate site after his second start likely because the Cubs didn’t need a fifth starter for a bit so he is expected to return rather soon. The 26-year old is still primarily a streamer, but keep a close eye on him as he could play his way into a firm hold in most formats if he can keep the walks and homers in check. Trevor Rogers, MIA | +6 to 19% The improvement of Rogers’ fastball is driving both his SwStr% surge and overall fast start (2.40 ERA/1.13 WHIP in 15 IP). It’s up 1.6 mph to 95.2 mph and has jumped from a 12% SwStr% to a 22% mark, 2nd to only Jacob deGrom (23%) among the 32 pitchers with at least 150 heaters thrown. They are running two times the league average SwStr% for a fastball and it won’t surprise you to learn that the other three in the top 5 are also dominating: Carlos Rodón (18%), Tyler Glasnow (17%), and Aaron Nola (17%). The 23-year-old lefty has been one of the early breakout pitchers to gain all formats viability after barely being drafted in many leagues. Both his personal development and the reputation of the Marlins to develop young arms fueled my interest in him and while I obviously don’t expect him to maintain a sub-3.00 ERA, especially if he continues to walk guys at a 15% clip, I do see him maintaining roster viability across all formats for the rest of the season. Michael Wacha, TBR | +5 to 16% Wacha’s career high SwStr% comes after a big pitch arsenal shift that has him throwing his four-seamer a career low 32% of the time and putting it into his cutter at 38%. He is still using his go-to changeup quite a bit at 28%, the second highest rate of his career. All three pitches are generating at least a 15% SwStr% rate. It’s been a less-is-more situation with the four-seamer as his more selective usage has helped him generate a 9-point jump to 16% SwStr%. The cutter is up 7 points to a 16% SwStr% and it has been his best pitch thus far with a 1.8 Pitch Value. The changeup is down 3 points to 19%, but still above the 16% league average from 2019-21. His 20 strikeouts in 15 innings are even more impressive when you consider his schedule has been at BOS, v. NYY, and at NYY. His 3.99 SIERA last year showed off some of his core skills, but an obscene 2.4 HR/9 kept him from finding any real success in 34 IP. His 0.6 HR/9 so far this year is his best mark since 2014 and as long as he can hold at or below 1.0, Wacha has viability across the fantasy landscape.