Both of these things can be true:
1. Gerrit Cole just finished one of the most remarkable stretches by a pitcher in Major League Baseball history.
2. Gerrit Cole was extremely fortunate during said stretch.
First, a primer for those who just started tuning in to Cole once he began donning New York Yankees pinstripes: On Wednesday, Cole lost a regular-season game for the first time since May 22, 2019. He set records and was the most overpowering pitcher in baseball during his stretch of 28 unbeaten starts, during which his personal record was 20-0 and his team's record was 25-3.
Cole struck out 270 batters in the games between his two most recent losses, which came on May 22, 2019, and Aug. 26, 2020. That was the most strikeouts between losses in MLB history. The previous record was held by Roger Clemens, who struck out 240 batters over a span of 30 starts in 1998 and 1999, which was the longest undefeated stretch of starts in MLB since the mound was placed at 60 feet, 6 inches in 1893.
At one point during the unbeaten run, Cole struck out at least one batter in 66 consecutive regular-season innings -- that was the longest streak in MLB's expansion era (since 1961) by more than 25 innings, according to the Elias Sports Bureau.
On the strength of 13.87 K/9 IP from May 27 until the end of the 2019 season, Cole set the single-season strikeouts per 9 innings record at 13.82.
Cole did it with power pitching. He had 147 strikeouts on pitches 95 mph or faster -- 39 more than anyone else in baseball -- and seven strikeouts on pitches 100 mph or faster; all other starting pitchers in baseball combined for four strikeouts on 100 mph pitches over this span. Nothing was more emblematic of this throw-it-through-a-brick-wall mentality than when, on July 6, 2019, on his 110th and final pitch of the night, Cole fired a 101.1 mph fastball past the Angels' Jarrett Parker. It was the fastest pitch of Cole's career and the fastest strikeout pitch by a pitcher at least 100 pitches into an outing since teammate Justin Verlander also hit 101.1 on a strikeout of Torii Hunter on pitch No. 114 of his evening nearly nine years earlier. Young Verlander was revered for his ability to throw his hardest when he knew the finish line was in sight. Cole is wired the same way.
During Cole's streak, which lasted from May 27, 2019, to Aug. 19, 2020, he led MLB pitchers (with at least 100 innings pitched) in strikeouts (270), strikeouts per 9 innings (13.30), WHIP (0.83) and, of course, wins (20).
Wins are a controversial stat these days in baseball circles and it's obvious why. Cole pitched to a 1.97 ERA in the same timeframe that Jacob deGrom posted a 1.91 ERA. So we'd expect their W-L records to at least be similar, right? Well, while Cole's was 20-0, deGrom's was 10-3. Run support is crucial.
And Cole received run support at a monumental rate. Cole's teams scored an average of 7.2 runs per game during his starts, which was the highest rate in MLB over this span (minimum 10 starts). There's no arguing that more than seven runs a game makes it a whole lot easier to avoid losses. Take Rick Porcello, who had one of the worst ERAs in baseball over this same span (5.99) but was in the top 10 in average run support (6.5) -- even he managed to post a winning record, at 12-11. Wins are the ultimate goal for every pitcher, but our accounting of them requires the most context.
There's another factor that needs to be mentioned, and of course the run support is ensconced within this: Cole pitched for juggernauts. The Houston Astros won a league-high 107 games last season and they were winning even before Cole got there -- he arrived on the heels of the now-controversial 2017 World Series title. And this year's Yankees were tabbed by Caesars Sportsbook to win the second-most games in the league and have mostly looked the part, getting off to a 16-10 start. Cole has pitched for the elite of the elite.
Getting traded from the Pirates to the Astros when Cole did was like winning the lottery. Signing with the Yankees after his time in Houston was Cole investing his winnings in a safe, secure spot -- a spot that could turn him from a pitcher who had a dynamic two-year run into an icon and a Hall of Famer. According to Elias, John Lackey (2015 Cardinals, 2016 Cubs) is the only pitcher in MLB history to qualify for the ERA title in consecutive seasons for two different teams with the best record in baseball. Cole could very easily be the second.
Cole was given often superfluous run support (he won a game 21-1 last season) and was around constantly winning clubhouses, but his teammates never had to bail him out of a horrible start during the streak. Cole didn't allow more than four runs in any of the 28 starts, and his shortest outing was 4⅔ innings in a seven-inning game.
Amazingly, there was only one game during the streak in which Cole left as the pitcher on the short side -- that is, in line for the loss.
On Aug. 28, 2019, Cole walked out to the mound for the top of the seventh inning of a 3-3 game against the Tampa Bay Rays. Joey Wendle led off with a triple, and after Cole struck out Willy Adames, Jesus Aguilar grounded an RBI single off a curveball. Cole then punched out Mike Zunino for his 14th K of the night and departed down 4-3. Will Harris relieved Cole and recorded the last out of the seventh. In the bottom of the inning, Yuli Gurriel led off with a walk, and the next batter, Aledmys Diaz, knocked him in with a double, tying the game. The Astros eventually won 8-6.
Cole was on the hook for a loss while out of a game for a grand total of 14½ minutes during the entire streak.
When Clemens went 30 starts in a row without a loss, he threw his last pitch with his team losing six different times, including a game in which he was knocked out after two innings, down 5-0. But overall, Rocket's run support (5.4 runs per game) paled in comparison to Cole's.
There's one remarkable parallel between Cole's and Clemens' unbeaten runs: Both joined the Yankees while already in the midst of identically lengthy streaks. Clemens was unbeaten in his last 22 starts as a Blue Jay in 1998. Cole was unbeaten in his last 22 starts for the Astros in 2019. But in most other comparisons, Cole comes out on top: Cole never allowed more than four runs in any of these starts, while Clemens allowed five-plus runs three times, including seven earned in three innings on April 15, 1999, vs. Baltimore. Cole's ERA was 0.71 lower (1.97 to 2.68), and seven different pitchers with at least 100 innings pitched had lower ERAs than Clemens while he put together his run for the ages.
Jake Arrieta is actually the man with the best argument that his own undefeated run was more impressive than Cole's: Arrieta pitched to a 20-0 record with a 1.01 ERA over his 24-start unbeaten streak in 2015 and 2016. Arrieta didn't have Cole's strikeout total (170 to Cole's 270) but was by far the more effective run preventer. So perhaps in some minds, Cole will have to settle for the second-most dominant unbeaten stretch of his generation. And somehow, Cole's hasn't yet resulted in a Cy Young award, something both Arrieta and Clemens took home at the end of the first season of their record stretches. Verlander's 2019 was special in its own right, but Cole's overpowering fastball and unrelenting refusal to lose made him the most valuable pitcher in baseball in 2019 (and yes, he was tops with 7.4 WAR, according to FanGraphs).
However, also according to FanGraphs, neither Cole (6.4) nor Arrieta (5.5) was worth the most wins above replacement over the duration of their respective unbeaten runs (trailing deGrom and Clayton Kershaw, respectively). In the end, there is no perfect way to evaluate a pitcher, but if there were, we know wins and losses wouldn't factor into it much.
So no, this isn't an answer to the Gerrit Cole vs. Jacob deGrom debate. Cole just finished up a fairy-tale run deGrom could never have accomplished -- the Mets just haven't allowed it to be possible.
But Cole, an elite pitcher -- perhaps one day an all-time great pitcher -- was an Astro and is now a Yankee. And he capitalized as few pitchers ever have.