On July 5, the Boston Red Sox edged the Los Angeles Angels to push their record to an astounding 54-32. This was a Boston team that was expected to loiter in self-inflicted mediocrity, but it was suddenly four-and-a-half games up on the second-place Tampa Bay Rays and 10.5 ahead of the dejected, fourth-place New York Yankees.
The Red Sox had swept the Yankees twice over the previous month, once in Boston and once in the Bronx. In a season where the San Francisco Giants were pulling off a similar and frankly more amazing trick, a narrative was picking up steam fast. Former Rays executive Chaim Bloom had assembled an overperforming band of bargain bin finds and outflanked the Yankees’ army of high-priced tanks.
The win over the Angels was par for the course for the 2021 Red Sox to that point. Multi-team castoff Christian Arroyo added a home run to star third baseman Rafael Devers’ big day. Journeyman starter Martin Perez allowed just two runs (one earned) over 5 1/3 innings and got the win.
A common question simmered for the soaring Red Sox and the flatlining Yankees: How is this happening?
Six weeks later, the gap has vanished, and so has the narrative. After sweeping a doubleheader Tuesday, the Yankees are percentage points ahead for second place in the AL East and the second wild-card spot. And the virtual tie will be broken by Wednesday night’s series finale in New York.
A tale of two seasons has already played out, and a third act will decide the ultimate impressions of how the rivals ran in 2021.
How the Yankees turned the tables on Boston
Before the season, the easily identifiable weak point for the Yankees was health track record. A chunk of their starting rotation and several key cogs in their lineup had struggled to stay on the field. And, well, that certainly played a role in their sluggish first half.
By the calculations at Baseball Prospectus, the Yankees have lost the third-most projected production to injury of any team this year (behind only the Dodgers and Mets). Long-term absences for first baseman Luke Voit, and outfielders Aaron Hicks and Clint Frazier forced them into scenarios where they were starting guys they had foreseen as minor-league depth or waiver wire fodder — including but not limited to Greg Allen, Chris Gittens, Estevan Florial, Ryan LaMarre and Jonathan Davis. Another emergency outfield option who is totally a real person, Trey Amburgey, didn’t make it through two full games before he, too, got hurt.
Injuries and offensive underperformance settled over the team like a malaise. At the All-Star break, the preseason AL favorites had sunk to +2000 long shots to win the World Series at BetMGM. That desperation also arguably inspired Brian Cashman’s dramatic trade deadline overhaul. Acquiring Joey Gallo and Anthony Rizzo, currently working his way back from COVID-19 infection, gives them an abundance of choice at first base and in the outfield.
Bloom and the Red Sox, meanwhile, took a trade deadline approach that could reasonably be called resting on their laurels, happy to continue playing with house money. They attempted to address a gaping hole at first base by acquiring the injured Kyle Schwarber from the Nationals, hoping to teach him the position. They did not take steps to supplement a starting rotation that always had a MacGyver feel to it, and that had been coming unglued since the June crackdown on sticky substances.
In the aftermath of the trade deadline, there was no question that the Yankees had more talent on the roster. The only question was whether it would have enough time to manifest in the standings.
Was the Yankees’ rise inevitable?
Much of the turnabout has been driven by that constant force we logically know exists, but eternally fail to see coming: Regression. Players tend to perform as we expected them to over large enough samples.
Take Gleyber Torres. Through July 4, the Yankees shortstop who walloped 38 homers in 2019 was batting a dismal .238/.328/.308 despite walking and striking out at his normal rates. That came on the heels of a down 2020, but even in last year’s shortened season, Torres was an above average hitter. Over the next month, before he hit the IL with a thumb injury, Torres kicked it into gear, batting .293 and doubling his homer total.
Offseason rotation acquisition Jameson Taillon — having missed almost two full seasons due to injury — understandably showed rust out of the gate, pitching to a 5.43 ERA prior to July 4. Since then, he has found a groove and fired eight stellar starts with a 1.68 ERA. The point isn’t that he’s now a sub-2.00 ERA arm, but that his overall production now amounts to a 3.89 ERA, 10% better than league average by park-adjusted ERA+. And that lines up snugly with his career production coming into 2021 — a 3.67 ERA and 112 ERA+.
That same trend that lifted the Yankees is tugging down on the Red Sox in a big way.
Since logging the July 5 win over the Angels, Perez is running a 7.77 ERA and has lost his rotation spot. Garrett Richards — who openly said the sticky stuff crackdown threw him off — has compiled a 5.74 ERA over the same stretch. Even the solid Nathan Eovaldi has hit a rough patch, sinking into a familiar pattern of allowing too many home runs. On Tuesday, he lost one of the games to the Yankees by allowing two runs on two homers.
With their records even, the rest of the season will pit them against each other, as well as the Oakland A’s and Toronto Blue Jays in a sprint for two playoff spots.
FanGraphs’ playoff odds give the Red Sox — who have an easier remaining schedule — a slight edge, with a 78.1% chance of making it into October compared to the Yankees’ 70.9% chance. Both teams’ projections lead the A’s and Blue Jays, even though the A’s currently hold the top wild-card spot. The PECOTA system at Baseball Prospectus gives the Yankees and A’s the best odds of securing those wild-card spots.
And, tellingly, both systems give the Yankees the best chance among the group of winning the World Series. Vegas agrees. The Yankees’ title odds are back down to +1400 at BetMGM, while Boston’s odds have ballooned to +2500.
On paper, we’re back where we started: The Yankees have more bankable talent. Now it’s a matter of whether it plays out on the field over the final 40+ games.
More from Yahoo Sports: