J.D. Martinez and his Red Sox teammates know two versions of Mookie Betts.

The first Mookie Betts is the one the rest of us see on a daily basis in the summer, the superstar making spectacular catches in the outfield, spraying line drives and home runs all around the ballpark and terrifying opposing defenses with his speed and smarts on the base paths. And he’s the one making everything look easy, dominating the game with his ever-present smile.

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“I just love that he is such a laid-back guy, he gets along with everyone,” Martinez told Sporting News.

And then, there’s the other Mookie Betts.

“Then when you talk about hitting, he gets very serious,” Martinez said. “It is almost like he wants to learn too much. He watches every guy and wonders about what he is doing, how his hands are, how he drops his elbows, and he always wants to see if there is something he can get from watching other guys.”

For Betts, watching and learning is an incredibly important part of the process. And not just watching and learning, but understanding how to use that knowledge to make his game better. And, yeah, he just keeps getting better and better.

Betts was a runaway choice as Sporting News’ 2018 MLB Player of the Year. As always — the SN award dates to 1936 — this honor is voted on by the players.

In a survey of 305 MLB players, Betts was first with 127 votes; Martinez was second (68), Christian Yelich was third (37) and Mike Trout was fourth (20). Ballots went out in early September and were turned in by the end of the regular season; a total of 19 different players received votes (only one name is allowed per ballot).

Betts is the fourth Boston player to win the award. Ted Williams was voted SN Player of the Year five times — as opposed to just two MVP awards voted on by the BBWAA — and Carl Yastrzemski (1967) and Roger Clemens (1986) also took home the award.

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Even though David Price wasn’t specifically talking about this award, it was pretty obvious during the ALDS that he would agree with the results of his fellow players’ voting.

“He's Mookie Betts,” Price said. “He’s the MVP of our team. He's the MVP of baseball.”

Betts’ improvement over the past few years is nothing short of amazing.

Remember, he finished second in the AL MVP voting in 2016, with a 9.7 bWAR, 42 doubles, 31 homers, 26 stolen bases and 122 runs scored. In 2018, with 116 fewer plate appearances thanks to a stretch on the disabled list with an abdominal strain, Betts had a 10.9 bWAR, 47 doubles, 32 homers, 30 stolen bases and 129 runs scored. That’s crazy.

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And those are just the counting/cumulative stats. As you can imagine, his percentage/sabermetric stats were much, much better this year, too.

In 2016, Betts produced a .315/.363/.534 slash line, good enough for an .897 OPS, 133 OPS+, 136 wRC+, .216 ISO and .379 wOBA.

In 2018: .346/.438/.640, 1.078 OPS, 186 OPS+, 185 wRC+, .294 ISO and .449 wOBA.

At this point, it almost feels like we’re trashing Betts’ 2016 stats, right? We’re not, of course, but just trying to show how much better Betts is now than in 2016 — and he was deemed the second-best player in the AL in 2016. That is bonkers.

“Really, he’s got a near-perfect swing for him,” Martinez said. “When he drops his elbows, for his body, he does it so well, he keeps his arms so soft and that allows him to react to the pitch as he is swinging. But he has no ego or attitude; he always thinks he can be better. He’s just a special guy, a young guy who is really mature.”

Even more amazing is how Betts put up middle-of-the-order power numbers from the leadoff spot. Historic numbers.

“He's definitely been our spark plug,” Boston ace lefty Chris Sale said. “When you're facing Mookie Betts the first batter of the game, that's a tough role.”

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Betts is the first leadoff hitter ever to lead his league in slugging percentage — and Betts didn’t just lead the AL with his .640 slugging percentage (.644 in the leadoff spot), he led all of baseball. In 2017, Charlie Blackmon became the first hitter with at least 550 plate appearances in the leadoff spot to finish a season over .600 (he was at .602), and before Betts this year, Rickey Henderson owned the AL’s best slugging percentage with at least 550 leadoff PAs, at .579 in 1990.

Speaking of Henderson, a Hall of Famer considered the best slugging leadoff man in baseball history, he only had one other season with a slugging percentage in the leadoff spot above .500 (.515 in 1988). During his power peak (1983-94, when he averaged 18 homers a year), Henderson’s slugging percentage was .465.

So, yeah, what Betts did in the leadoff spot this year was historic.

“He's been the same guy through it all, since I've been here,” Sale said. “And it doesn't happen by accident, neither. He puts in the work and shows up every day ready to go. I think there's a lot of other factors that go into it, but hard work pays off, and we saw it.”

The rest of baseball saw it, too, and that’s why his fellow players voted Betts the Sporting News’ Player of the Year.