How Much Should We Fear Giancarlo Stanton In Pinstripes?

After several weeks of involved trade discussions that would send prized Miami Marlins slugger Giancarlo Stanton to either the San Francisco Giants or St. Louis Cardinals, the baseball world was thrown a curveball Friday when it was reported that Stanton rejected both deals — and that the New York Yankees had swooped into the bidding. According to multiple reports, and assuming Stanton approves the deal, the Yankees had done on Saturday what the Giants and Cards couldn’t: They reeled in the game’s top power hitter.

There were only two hitters last season who hit more than 50 home runs in MLB. Now, the Yankees have both of them: Stanton and fellow right-handed behemoth Aaron Judge. There’s reason to think Stanton will like hitting in Yankee Stadium as much as his new teammate. According to The Baseball Gauge’s park adjustments, Marlins Park was the third-most-difficult home run-hitting park for right-handed batters last season, which had the effect of depressing righty homers by about 20 percent relative to an average MLB ballpark.²⁶ You read that right: Stanton smashed an MLB-leading 59 bombs — the most in baseball since 2001 — and took a serious run at Roger Maris’s pre-steroids HR record despite playing in one of the game’s most difficult parks for right-handed power hitters. There’s a reason Stanton was named NL MVP even though his team finished 20 games out of first place — it was one of the great individual seasons of this millennium.

If you use The Baseball Gauge’s adjustment and extrapolate Stanton’s 2017 homers to a typical park, he’d project to have hit about 66 homers — easily shattering Maris’s mark. What’s more, Yankee Stadium ranked as the third-most-favorable park in baseball for right-handed home run hitters last season. Continuing our exercise above to project Stanton’s season into Yankee Stadium, he would figure to have hit around 73 homers (!!!) if he’d played in the Bronx instead of Miami. Now, the obvious caveats apply: Park factors are imperfect measurements that don’t account for each park’s exact dimensions, instead inferring the effect in a somewhat noisy way by looking at the change in home runs between a team’s home and road games. But even so, Stanton is probably going to get some kind of assist in his power numbers simply by upgrading his park situation.

The real question for the Yankees is whether that boost will be enough to offset the tug of regression to the mean. Stanton had the best season of his career in 2017, and not just in the HR column, where he set a new career high by 22 homers. He also reached new career marks in isolated power, strikeout rate, on-base plus slugging and wins above replacement,²⁷ in addition to playing 150 games in a season for the first time since 2011. There’s a very good chance that last season was the best we’ll ever see out of Stanton, who still has at least 10 years and $295 million left on his gargantuan contract. It would be unfair to expect him to reproduce anything close to that level of performance, particularly given his history of injuries.

According to WAR, Stanton was worth 7.2 wins at age 27 last season, the first time he ever broke the seven-win barrier in a single season. Since 1920, 66 hitters have cracked 7 WAR for the first time between the ages of 25 and 29 (provided they also put up at least 20 career WAR from their rookie season through their breakout season).²⁸ Those players had that big year at an average age of 27.2 — roughly the same as Stanton last year — so they make for a good sample from which we can draw a comparison for Stanton’s next few seasons.

For our historical group — which includes the likes of Frank Robinson, Manny Ramirez and Tony Gwynn — the drop was relatively steep from their career-best season. On average, they fell from 8.0 WAR that year to 5.0 the following season, with the total diminishing over each of the next five years in a predictable aging pattern. Only 10 of the 66 ever had another season as good as their breakout campaign. Granted, Stanton’s big year was slightly less out of place with the rest of his career, so he’ll probably feel the pull of regression a bit less than other players might. And a batter who produces between 3 and 5 WAR is no bum — quite to the contrary, 5 WAR is roughly the border where All-Star seasons start to take shape.

Plus, the Yankees might not even need Stanton to reproduce his 2017 in order to have a great season next year: Their run differential suggests they were roughly as good as the 104-win L.A. Dodgers last year, despite winning “only” 91 games. New York would have been formidable without Stanton, and with him (plus Judge, Gary Sanchez and others), they’ll be a right-handed power-hitting squad the likes of which the game may never have seen before.

But at the same time, Stanton will probably not reach the heights of his performance from 2017 ever again — meaning the Yankees are getting a very good player but probably not one with perennial MVP potential. After all, there’s a reason they call it a “career year”: You only get one of them per customer.

Either way, after several relatively quiet offseasons, general manager Brian Cashman and the Yankees seem to be returning to their big-ticket superstar roots. Now we’ll see if they can also revive the tradition of winning World Series.