I’ve been waiting weeks to post something about Jake Diekman. After all, the best way to ruin a 0.00 ERA is to publish an article all about it. But on Wednesday, for the first time in 2020, in his team’s 55th game out of 60, the lefty reliever allowed a run.
The Oakland A’s acquired Diekman last year at the trade deadline. He didn’t yield his best results the rest of the way, with a 4.43 ERA and nearly one free pass per inning (including walks and HBP). That wasn’t enough for the A’s to pick up his hefty contract option over the winter, but they did decide to bring him back at a lower price on a two-year, $7.5 million deal.
Here’s what I wrote about that signing at the time:
I’m not so sure about this move. Diekman did not inspire confidence last year in his time with Oakland, and declining his expensive option was a no-brainer. This new contract is at least a better value, but is he the pitcher the A’s needed? And does he merit a multi-year commitment? I was ready to move on from him and figured the team had done just that, and this signing won’t be popular among the Athletics Nation community.
However, speaking as a silver-linings guy, remember that the reliever volatility pendulum can always swing back the other way. He’s got power stuff and he misses bats at a high rate, so there will always be upside for a big year at any time, even with all the walks. He’s not the reliever I would have picked, but it’s absolutely possible he can make good and be productive. At the least he’s nearly guaranteed to be better than what we saw from him last summer in the small sample after his acquisition — again, seriously, that was arguably the worst he’s ever pitched when healthy.
Cold takes exposed! Although I did at least hedge my bets by mentioning that talented relievers can always break out in any given season.
And whaddya know, that volatility pendulum did indeed swing back the other direction, all the way through the roof. Diekman has been unhittable this year — he still walks a ton of batters, but when they do swing they can’t touch him. It took until his 19th appearance of the year, 92% of the way through the abbreviated season, for him to finally allow a run, earned or otherwise. (He did allow one inherited runner to score back in mid-August, but even in that department he’s 2-for-3 in terms of stranding them.)
Diekman: 0.47 ERA, 19⅓ ip, 28 Ks, 11 BB, 1 HR, 8 hits, 2.66 FIP
The hammer finally came against the Los Angeles Dodgers on Wednesday, but from the last source you’d expect in their star-studded lineup. Lefty backup infielder Edwin Rios did the deed, launching a solo homer to tie the game in the 8th and hand Diekman a blown save — though Oakland did come back to win eventually, so the southpaw also vultured a relief win out of it.
There’s plenty to back up those numbers, too. Striking out 28 of his 76 batters gives him a whopping 36.8% rate, which ranks Top 20 in the majors among 476 pitchers with at least 10 innings pitched. Behind that is a 17.1% swinging strike rate, 22nd-best among that same sample group. And Statcast has his xwOBA at .258, which is 23rd out of 348 pitchers with at least 300 pitches thrown.
And even better, all of this improvement isn’t coming out of nowhere, in the way that might make you think it’s a total small-sample fluke that results in Diekman turning back into a relative pumpkin at some point soon. There was an actual change in his arsenal, as he picked up a new slider grip on Twitter back in July that vastly increased the movement he got on the offering, thanks to the Pitching Ninja sharing the method of Chaz Roe of the Rays.
Diekman already got great results with his old slider, but now it’s been among the best in the business. He’s thrown it 134 times, and the .143 xwOBA it has produced is the 11th-best in MLB among 246 hurlers who throw sliders and have at least 300 total pitches thrown. Among those who rely heavily on their sliders, with at least 100 thrown of that specific pitch this year, Diekman’s is fifth-best, after just Blake Snell, Corban Burnes, Felix Pena, and Yohan Ramirez.
When a pitcher has an 0.47 ERA and a .123 batting average against, you know those sparkling numbers won’t last forever. Nobody maintains that level forever. But the good news is, even though a few hits will eventually fall and a couple more runners will finally find the plate someday, Diekman still has every chance to continue being a reliably excellent reliever as the A’s venture into October.