George Kirby's Aggressive Usage Tweak. Kyle Harrison's Location Change

George Kirby, Kyle Harrison, Framber Valdez

• Mariners George Kirby has a 1.88 ERA and a 2.05 FIP since June 1—pure domination. It’s always good to check in on the aces and see what they’ve adjusted. In the month of July, Kirby has started throwing more splitters to righties. Usage has increased from 6% to 10%. More notably, he’s gone from not throwing it once behind in the count to righties from April-June to throwing it 15% behind in the count in July. This is a gutsy pitch to throw when behind because the zone rate of the pitch isn’t high, but I love the idea of it being used to mitigate behind-in-count damage, especially for a pitcher who can probably exist out of zone more without consequence given the sub 1 BB/9. 🔱

  • His splitter shape is also subtly different. It was -1” vertical break and 9” arm-side in May/June. It’s now 2” vert and 11” arm-side in July. It’s dropping less and running more. We see variance in splitters often, but Kirby’s are usually pretty tight in shape. I wonder if he’s playing with a new grip or cue. Versus lefties we see more curveball in July. Usage has doubled from 9% to 18%. This pitch is mostly thrown to lefties ahead in the count, where we’re now seeing the usage push over 25%.

• Giants Kyle Harrison is trying a new approach with his slurve to righties. Instead of putting the pitch middle, he seems to be back-dooring the pitch, trying to catch the outer third of the plate (see heatmaps below). Small sample results look good, but it’s mostly because nobody is putting the pitch in play with this approach. He’s also backed off his fastball usage since returning from the IL too. He was 61% fastball before and he’s been 49% since. His slurve has jumped up as a result, now sitting above 25% usage. His changeup has taken most of the heat in terms of damage allowed in these past few starts, but his overall results have improved. 🌉

  • I’m still somewhat stunned there isn’t another pitch in his mix here. Something that can move glove-side in the mid 80s feels like low-hanging fruit. It feels like something down-in would help a ton. Or even some kind of true sinker for him if he’s able to locate arm-side away to lefties well enough. The hesitation might be due to his velocity limitations on the hard slider and <88 mph not working down-in, but a boy can dream. I’m not convinced the backdoor slurve is the answer, but I like it as a weapon to go to. We’ll see how long it helps him out.

Kyle Harrison’s slurve location to righties (April-June vs July)

• Astros Framber Valdez’s velocity is up ~1 mph in July. He’s now sitting 94.5 mph on his sinker instead of 93.6 mph. We see a similar velo jump for his curve and changeup. He’s backed off his sinker usage to righties as a result (that’s modern baseball). He’s down to just 40% in July compared to 53% in May/June. His curveball has increased in usage as a result of the anti-sinker approach. His swinging-strike rate against righties has jumped from 11% to 15% with the decrease in sinker too. Positive results overall, as he’s quietly tracking for another mid-3s ERA season, even if this year his strikeout rate is down below 21% for the first time in his career. 🤠