Will David Ortiz be a Red Sox problem at 40?

David Ortiz has made a whole career out of defying the odds, something Red Sox fans have long gotten used to at this point. Originally acquired off waivers to back up Jeremy Giambi in 2003, Ortiz is still swatting home runs at a near-unparalleled level for Boston 12 years later.

Although I certainly wouldn't be the first to point out that Big Papi has aged gracefully for a power hitter, it's worth noting, year after year, just how remarkable Ortiz's career has been. Last season, at the age of 39, he shook off a slow start to hit .273/.360/.553 with 37 home runs and a 141 OPS+. If those impressive numbers don't surprise you, that's because Ortiz has made such excellence par for the course.

Indeed, Ortiz has posted an OPS+ of 140 or higher in five straight seasons, which is only made more impressive by the fact he's done so while steadily approaching his 40th birthday. The late thirties are generally unkind to power hitters, but age hasn't had the same adverse effect on Ortiz's production. He's hit over 30 homers in four of the past six years and slugged over .500 in every campaign since 2009.

With retirement awaiting after next season, whether Ortiz can excel again offensively is a storyline that bears watching in 2016. For while the veteran slugger has shown little sign of decline in recent years, hitters who have reached their 40th birthday rarely post the kind of numbers that we've grown accustomed to seeing from Ortiz.

According to the Baseball Reference Play Index, in fact, just five different hitters have slugged over .500 after turning 40 years old (min. 400 plate appearances), with Barry Bonds achieving the feat on two occasions:

Perhaps more notably, other than Bonds (who really deserves to be in his own category), just four batters have posted a slugging percentage over .500 once they've turned 40, and none have done so since Harold Baines in 1999. That's quite the low number, even if we acknowledge the obvious fact that hitters typically don't thrive upon reaching their fourth decade in life. It's also worth remembering that, when Baines slugged .500, offense was pretty inflated compared to today.

Nonetheless, such a stat speaks to just how rare Ortiz's enduring excellence has been and how hard of a task he'll face in trying to record his sixth straight campaign with a slugging percentage of at least .500 in 2016. For someone who has achieved just about everything in his career, Ortiz has the chance to enter even more rarefied air and accomplish something no hitter has since Bonds.

What has proven even more difficult for 40-year-old sluggers throughout MLB history is that 30-homer plateau. Just one hitter, Darrell Evans in 1987 (whose same season also appeared on the previous list), has hit at least 30 home runs after turning 40. That's even more remarkable, especially considering seven batters have belted 30 long balls or more at the age of 39 in baseball history.

Now doubting Ortiz has long been a fool's errand, and it wouldn't surprise anyone to see him leave the game amidst one last glorious blast of long balls and plodding home-run trots. Yet these past performances demonstrate just how hard it is to remain dominant so late into one's career.

Whether Ortiz can reverse this long-held trend remains to be seen. His first-half struggles last year were a reminder of how quickly things can go downhill for a veteran in the twilight of his career, just as his rebound over the season's final few months reaffirmed how exceptional he truly is. For someone who has held on so long, it's odd to think about how often there is speculation over an impending decline..

Now we know exactly when Ortiz's career will come to an end, even if his chances at success have never been smaller, at least in history's eyes. But what remains true about Ortiz to age 40 is the very reason he's still even playing at all; he's no ordinary hitter but rather someone who blows conventional aging curves out of the water.

Boston's beloved slugger shares company with another group, even more impressive than that in the table above. Among hitters in their age-39 season, only five have posted an OPS+ of at least 140, Ortiz and four others: Bonds, Ted Williams, Willie Mays and Babe Ruth.

That's the company David Ortiz keeps, and it's the reason why he has the chance to record one of the best age-40 seasons in baseball history.