Pitching transformations seem to be sustainable. Pitchers are streaky, research proves. And most of the production is tied to positive movement in average fastball velocity. So let’s look at performance since the All-Star Break and see if we can ride hot hands to a championship.
We’re going to examine ERA and the stat that is most stable in small samples, (Ks-BBs)/IP. The thing we know for sure about the hot pitchers is that they are healthy, which is probably a bigger part of good pitching than we know. And we’ll also look at some big names who are faltering.
Let’s start with a big name who has turned it around when many, including me, just figured it was over: Justin Verlander. The future Hall of Famer has a 2.48 ERA since the break and a sterling .883 (Ks minus BBs) divided by innings pitched. The average of the 61 pitchers with at least 40 innings since the break (entering Wednesday) is .662. Verlander somehow has boosted his velocity significantly over where it was the past two seasons, to over 95 mph on average.
I’m relieved our models identified Sonny Gray as an ace-worthy fantasy buy. He’s come through with a third-best 2.18 ERA even though I must note his Ks and BBs have regressed below average .508. He’s been passed in those categories by someone my model said to sell but who just keeps defying gravity, Gio Gonzalez, an MLB-best 1.29 ERA since the break. But at least Gonzalez has boosted these peripherals up to a semi-respectable .555.
Lance Lynn I wouldn’t trust as far as I can throw him with 31 Ks and 20 BBs in 48.1 IP in the period. That’s a .228 (K-BB)/IP. But remember that ERA is much more volatile in these smaller samples than the Ks and BBs, which are stable in this admittedly arbitrary sample. But the top 10 in the foundational Ks and BBs have an ERA on average a half a run higher (3.48) than the bottom 10 (3.98). Over time, I would expect this gap to increase. Looking at it the other way, the top 10 in ERA has a (K-BB)/IP of .69 vs. .54 for the bottom 10.
But pitchers you can buy are Trevor Bauer and Patrick Corbin. They line up perfectly at 2.83/.774 and 2.84/.750, respectively. They are owned now in at least 64% of leagues but the point is that you should not bail on them if they have one poor start. They have earned a longer leash. Carlos Rodon has been dominating in the peripherals (.847) more than ERA (3.71). However, he’s similarly owned.
A deep cut very likely to be available who should be okay in a mixed-league rotation is Chad Kuhl (10% owned), who 3.60 and .525. He should be able to hold that ERA for the remainder of the season.
Another pitcher less than 50% owned for reasons I get is German Marquez of the Rockies. Yes, Colorado. But that 4.01 ERA since the break is sustainable plus you are adding solid Ks (46 in 42.2 innings with a sterling .797 number in our stat). And he’s very projectable with average velocity of 95.2 mph (which would be top 10 if he had enough innings).
On the bad side of the ledger are some big names. Carlos Carrasco has been pounded 5.12 ERA, but it makes no sense with his (K-BB)/IP of .857. Bet that Carrasco is still an ace. Dan Straily hasn’t really collapsed as his 5.10 ERA has indicated (.560). Ditto Jeff Samardzija (4.89/.624) and Jon Lester (4.69/.893). I’d take Lester, even being on the DL for what’s expected to be one or two more starts, for example over the much hotter (in ERA) Jake Arrieta (.600 in our peripheral stat).