Red Sox

This is the single biggest reason for Red Sox not to sign Mookie Betts long-term

Red Sox

Whoever gives Mookie Betts a 10-year contract will pay him to be an all-time great.

Tell me how many of those greats stand 5-foot-9.

There is no questioning Betts' preeminence at this moment. The former MVP is one of the five best players in baseball, and when everything is clicking, he's the only human alive who can challenge Mike Trout for five-tool dominance.

But anyone giving him 10 years and $300 million, like the Red Sox reportedly offered, or 12 years and $420 million, like Betts reportedly wants, must determine the likelihood that he'll remain productive well into his 30s.

LIVE stream the Celtics all season and get the latest news and analysis on all of your teams from NBC Sports Boston by downloading the My Teams App.

And if there's one number that should give everyone pause, it's the one he can't do anything about — his height.

Undersized stars simply don't last, no matter how many MVP awards they win in their 20s. We laid this out recently, but it's worth examining in greater depth.

Since integration in 1947, only seven players 5-9 or shorter have compiled 50 career WAR: Joe Morgan (100.6), Tim Raines (69.4), Pudge Rodriguez (68.7), Yogi Berra (59.3), Luis Aparicio (55.8), Dustin Pedroia (51.7), and Kirby Puckett (51.1). Betts (42.0) should join them sometime in early 2021.

By comparison, 125 players 5-10 or taller have cracked the 50-WAR plateau in that time, from Barry Bonds (162.8) to Torii Hunter (50.1).

Morgan, Raines, Rodriguez, and Pedroia each delivered their last standout offensive seasons at age 32, while Berra remained an All-Star into his late 30s. Aparicio was a remarkably below-average offensive player even in his prime — he reached the Hall of Fame with a lifetime OPS of .653 — and that leaves Puckett, who's the tragic best-case scenario.

 

The Hall of Famer remained an offensive force through age 35 before a freak eye injury ended his career. He made his 10th straight All-Star team in his final season while batting .314 with 23 homers and 99 RBIs.

Had he signed a 10-year deal at age 28, he would've been worth it. The others on this list, not so much.

For proof, Red Sox fans need look no further than Pedroia, a gritty, gutsy, MVP-caliber sparkplug whose body simply couldn't take the pounding. The 5-foot-8 former All-Star signed an eight-year, $110 million extension in 2013 that runs through 2021.

"If we're going to bet on someone at 37 or 38 years old, we're not sure there's a better guy to bet on," general manager Ben Cherington said the day the extension was announced, unaware that Pedroia would play his last effective game at 33. They'll likely have three hits in nine games to show for the final four years and $56 million of their investment.

If there's a saving grace from a roster-building standpoint, it's that Pedroia only banked a relatively modest $14 million a year. He long ago earned every penny of his $110 million. However, betting on your guy to buck the trends when we're talking about $400 million is a very different gamble.

Only three players Betts' size since 1980 have delivered a .900 OPS in at least 100 games after age 30 — Matt Stairs (twice), Lonnie Smith, and Puckett. Assuming Betts plays out this season and signs a long-term deal that starts in 2021 with his age-28 season, would you pay him $35 million annually into the next decade for an OPS that doesn't crack .900 after 2022?

Consider how Betts generates his power. He relies on lightning-quick wrists, because he's never going to muscle his way out of the park like Albert Pujols or Miguel Cabrera or Adam Dunn. Virtually all of his homers are to the pull side, because he lacks the bulk to consistently launch them out the other way.

What happens if he breaks a hamate, or tears a thumb ligament, or sprains his wrist? Both Pedroia and Nomar Garciaparra looked like they were on their way to Cooperstown before hand injuries robbed them of their reflexes at the plate. Neither one ever sniffed $35 million a year.

Betts has earned the right to seek that rate, and someone will almost assuredly give it to him. Just don't be surprised when they end up with a case of buyer's remorse, because players his size simply aren't built to last.