Diamondbacks Pitcher of the Year: Patrick Corbin

There were at least two points in Patrick Corbin’s career where him winning this award for the second time seemed very unlikely. The first was at the beginning of the 2014 season. Our reigning Pitcher of the Year was robbed of a chance to be our Opening Day starter in the Sydney series, by an elbow injury that required Tommy John surgery. Coming back from that is always a roll of the dice, but Corbin recovered and took the mound for the second half of the 2015 season. But his campaign the following year was terrible, and in mid-August, with an almost Shelby Miller-like ERA of 5.58, Corbin was moved to the bullpen. We’ve seen pitchers go that way and never come back e.g. Archie Bradley and Daniel Hudson, so there was legitimate concern we’d seen the last of Patrick as a starter.

However, Corbin was returned to the rotation in 2017 and provided a solid season, posting a 4.03 ERA, and not missing a start. That set the table for his final year before free-agency, and a thoroughly motivated pitcher came out of the gates firing. With Zack Greinke’s groin tightness keeping him out for a few days, Patrick finally achieved the Opening Day start for Arizona he had been denied four years previously, and got the W in an 8-2 victory over Colorado, throwing 5.2 innings of two-run ball. Much better was to come, however, as he went undefeated in his first eight starts. He blanked the Dodgers for 7.1 innings of one-hit ball on April 4, then one-hit San Francisco 13 days later, our Performance of the Year.

That was just the best of many very good performances from Corbin. He had two games where he struck out a dozen opposing batters, walking one and zero hitters. That made him the first Arizona pitcher with multiple games like that (12+ Ks, 0/1 BB) in a season since Randy Johnson in 2004. His 12 strikeout, no walk outing on June 22 in Pittsburgh was also only the second such since then (Robbie Ray had the other, in 2017). When Patrick had his slider working, he was almost unstoppable: across the nine games where he had 9+ strikeouts, he allowed only 37 hits in 59 innings, with a staggering K:BB ratio of 90:7, with a WHIP of 0.75.

It was an especially remarkable performance, considering there were concerns about his diminished velocity in May, leading to articles with headlines like The Diamondbacks Could Have a Patrick Corbin Problem. His four-seam fastball averaged 92.8 mph in 2017, but against the Dodgers on May 3, was only 89.7 mph. While both pitcher and team professed no great degree of worry about the suddenly missing mph, the Diamondbacks were bothered enough to have Corbin skip bullpen sessions between starts. The velocity did eventually return, but took its time about it, Patrick not averaging 92 mph again until September. However, you’d be hard pushed to say that he missed it.

A key factor this year was his ability to get out right-handed batters. Look at the difference in his split against them, comparing last season to this:
2017 vs. RHB: .292/.348/.482 = .830 OPS, K:BB = 2.41
2018 vs. RHB: .213/.259/.324 = .583 OPS, K:BB = 5.67
Right handed-batters hit almost two hundred and fifty points worse against Corbin last year, and struck out in 30% of the plate-appearances. You’ll know why, if you watched one of his starts. You would have seen him deliver a Big Unit-esque slider, diving in to the ankles of right-handed batters.

It wasn’t nearly as hard as Randy Johnson’s 98-mph “Mr. Snappy”, averaging only 91.3 mph. But it was particularly effective when combined with a slower version - classified by Pitch f/X as a curve, coming in at 72.8 mph. He used this a lot in fastball counts, either to get back into the count or get ahead. And he did so regularly, getting strike one a career-high 64.2% of the time, which put him the driver’s seat. After that first strike, batters were held to the tune of .191/.239/.287. Few pitchers generated less contact than Corbin: at 25.7%, his swinging strike rate was the highest of any qualifying pitcher in the majors, and the overall contact rate of 65.3% trailed only Chris Sale (65.0%).

The resulting strikeout rate of 11.1 per nine innings was more than 30% up on the 2017 figure, which was already a career high for Patrick to that point. He became one of only fourteen qualifying pitchers in baseball history with a season where their K-rate was better than 11 and their K:BB ratio was above 5. [Though in a startling testament to the rise of the K in recent times, nine of those have come over just the last four years, with Randy Johnson, Curt Schilling and Pedro Martinez the only men to have done it prior to 2014] His All-Star selection in July - the second for Corbin, following on from 2013 - was testament to that, as was his fifth-place finish in Cy Young voting.

He was a free-agent this winter, and got what is to this point, far and away, the biggest contract of the off-season. Corbin signed a six-year deal with the Washington Nationals, worth $140 million - that’s more than twice the next-highest in total value, the four-year, $68 million deal inked by Nathan Eovaldi with Boston. His departure undeniably leaves a big hole in the Diamondbacks rotation for 2019 that will be hard to fill. He leaves Arizona fourth on the all-time franchise list for wins (56), third for strikeouts (897), and seventh for pitching WAR (11.4). His 246 K’s last season were the most by any non-Johnson/Schilling player, and the highest figure for Arizona since 2004. The ‘Pittie for Best Pitcher was well deserved.