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At the end of 2016, Hub fans will finally bid adieu to Big Papi. And also, welcome his heir.

David Ortiz made it official two months ago that the 2016 season will be his last. When he did, he set a countdown to the moment when the Boston Red Sox will part ways with a player who's slugged 503 home runs and won three World Series titles on his way to becoming one of the franchise's great icons.

Lucky for them, at least they have a player who's ready to fill Ortiz's shoes. His name is Mookie Betts, and 2016 should be the year he becomes the new face of the Red Sox.

Now, let's grant that the Red Sox aren't short on candidates to wear their face after Ortiz calls it a career. The 40-year-old designated hitter is surrounded by star newcomers David Price and Craig Kimbrel, ol' standbys like Dustin Pedroia and a wave of fresh-faced youngsters in Xander Bogaerts, Blake Swihart and Eduardo Rodriguez.

But the 2016 season should be all about Betts. That's in part because young homegrown studs who play every day are the best franchise-player candidates, and in part because the 2015 season was all about Betts.

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Though the Red Sox endured their second straight last-place finish in 2015, Betts was a major bright spot. Whether you consult Baseball-Reference.com or FanGraphs, wins above replacement pegged the young outfielder as Boston's best player. And according to FanGraphs, Dan Szymborski's ZiPS projections system predicts that Betts will once again be the best player on the Red Sox in 2016.

Hard to believe? Hardly.

Though Betts wasn't the best hitter on the Red Sox in 2015—that honor naturally belongs to Ortiz, who OPS'd .913 and slugged 37 dingers—there's no doubt he was Boston's best overall player. His first full season saw him hit .291 with an .820 OPS, 18 home runs and 21 stolen bases, with plenty of highlight-reel plays in center field on the side.

And because Betts did all that at the ripe young age of 22, it's only fair to have big expectations for what he might do at the age of 23 in 2016. If you're, say, Buster Olney of ESPN.com, you might even be thinking about Betts as a potential American League MVP contender:

These are some high hopes, all right.

But in Olney's defense, having high hopes isn't the same thing as having unreasonable hopes. Though Ortiz and his grand farewell will be front and center for at least the start of 2016, it's not at all difficult to imagine Betts will steal the show.

When dealing with great all-around players, there are typically areas where you can count on continued greatness without any second thoughts. With Betts, those would be his baserunning and defense.

Though Betts stole "only" 21 bases in 2015, FanGraphs' BsR metric (baserunning runs above average) actually rated him as MLB's best baserunner. That's thanks to all the more under-the-radar plays he made on the bases. And according to the defensive metrics, Betts' defense in center field was somewhere between above average and way above average.

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This had much to do with Betts' plus speed, which is likely still years away from declining. The only question is whether his proposed move from center field to right field will hinder his defense, but it's not much of a question. Right field at Fenway Park is basically a second center field, and Betts teased at the end of 2015 that he's up to the challenge.

If there's a more palpable sense of doubt, it's in regard to whether Betts can repeat his offensive performance from 2015, much less improve on it. But this, too, is an area where there's room for only so much doubt.

The ideal hitter is one that has patience, can put the ball in play and can hit the ball hard. Betts showed in his rookie season in 2014 that he had the ability to do all three, and 2015 was basically more of the same. He got even better at avoiding strikeouts and hitting for power, and beneath his slightly subpar walk rate was a 26.2 chase percentage that easily beat the MLB average of 31.3.

Or, in Holmes-to-Watson terms: After teasing he could be one in 2014, Betts established himself as an advanced hitter with power in 2015. A rare breed, them.

And as far as Betts' advanced approach goes, even better is how it was actually more advanced at the end of 2015 than it was at the beginning.

While Betts had a tough time hacking at off-speed pitches in April, Brooks Baseball can show that he got better and better at laying off the stuff as the season went along. That speaks to his ability to adjust, which assistant hitting coach Victor Rodriguez very much approves of.

"That's one thing that makes him different, the ability to adjust from one at-bat to another, or sometimes from one pitch to another," Rodriguez told Tim Britton of the Providence Journal last May. "It seems like every game, he puts together good at-bats, not necessarily results, but working counts, taking pitches, making hard contact, taking a walk when they're giving it to him. That's a good sign."

Betts also adjusted how he was hitting the ball. If we refer back to Olney's tweet and use June 10 as a cutoff, it stands out that Betts stopped trying to drive the ball and just plain started driving the ball. He became less fly-ball happy and better at hitting the ball squarely:

Mookie Betts Before and After June 10 Span FB% LD Soft Hard Before June 10 44.2 18.8 17.6 28.1 After June 10 41.3 19.9 15.1 33.0 FanGraphs

Mind you, all this is arguably dodging the question that really matters: Can a guy listed at 5'9" and 180 pounds really carry on as such a good power hitter?

As it happens, there are some good answers out there. Betts' power mainly applies to pitches on the inner two-thirds of the plate, and Dave Cameron of Fox Sports broke down how Betts got really good at not missing those in 2015. And in a piece for Baseball Prospectus Boston, Matthew Kory highlighted how Betts didn't collect cheap home runs.

Are there things Betts legitimately needs to improve on? Sure. It would be nice to see more plate coverage, for one. For two, he could use more route efficiency to make the most of his speed on defense.

But...that's...pretty...much...it. The fact is it's hard to poke holes in Betts' game. There may not be any one thing in particular that he excels at, but he's quite good at everything. In him, the Red Sox do indeed have a budding superstar on their hands.

And yet, that's only half the reason Betts is the right guy to take over for Big Papi as the Red Sox's next franchise player.

Charles Krupa/Associated Press

It's one thing to be great, and another thing to be entertaining. The latter word fits Ortiz just as well as the former. His legacy consists of not just his big numbers and his World Series rings, but also his all-time great flair for the dramatic and his epic bat flips and home run trots. Never mind what he did. Nobody's ever going to forget how he did it.

Betts isn't going to copy Big Papi's special brand of entertainment. But he's shown he can be entertaining in his own way, mainly because he's not exactly casual in the application of his many talents. There's energy in Betts' game, and on any given day it can lead to one or more "Did you see that?!" moments.

That was never more evident than in Boston's home opener against the Washington Nationals early last April, in which Betts owned the day by robbing a home run, hitting a home run and tearing up the basepaths. He completely took over the game, making for a hell of a highlight:

That right there was one of the most electric individual performances of the 2015 season, and Big Papi himself was among those who was on the edge of disbelief.

"That was the craziest thing I've ever seen in baseball," Ortiz said, per Gordon Edes of ESPN Boston. "I was like, 'Bro, not even in a few practices you can do that.'

"That kid is an unbelievable athlete," Ortiz exclaimed. "It's a no-doubter he's going be a superstar."

Well, no argument here. Betts has already broken through as a star, and he has everything he needs to take the next step. By the time he's done with 2016, he should indeed be a superstar.

And when Big Papi is done with it, Betts will also be ready to become the new face of the Red Sox.

Stats courtesy of Baseball-Reference.com and FanGraphs unless otherwise noted/linked.