HOUSTON -- The odd offseason is moving quickly in one respect -- Spring Training is fast approaching. Still, some of the most attractive free agents remain unsigned.
Presumably, J.D. Martinez will be playing baseball somewhere this year. Even if he ends up signing for fewer years than he desires, Martinez undoubtedly will be among the top earners of his current free-agent class.
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Martinez is a compelling story, considering four years ago he was released by the Astros during Spring Training, and since then he has gone on to earn elite status as one of the game's best sluggers.
When he does sign his contract with the Red Sox or any number of mystery teams who have shown interest, it's highly likely what Martinez did with the Tigers and D-backs will lead the conversations, while his Astros years, though purposeful, are more likely to be viewed as an afterthought.

But for a couple of coaches tasked with shaping Martinez during his tenure with the Astros, those years were hardly a waste. It took Martinez a while to come into his own, but positive signs were there from the start.
"His balance, his body control, how he moved the bat through -- he was able to get those things first," said Brad Mills, Martinez's manager in Houston from 2011 until August '12. "He had a good foundation and a basis for hitting. That's huge."
Mills, currently the Indians' bench coach, admitted he couldn't have predicted that Martinez would hit 45 homers and drive in 104 runs in just 119 games last year. But he knew Martinez, at the very least, had the potential to be a great hitter soon after Martinez debuted in 2011. In his first month in the big leagues, Martinez drove in 28 runs, a rookie record.
Still, Martinez's numbers when he was with Detroit and Arizona from 2014-17 are gaudy compared to his slash lines during his three-year Houston tenure.
With Houston, Martinez slugged .387 and had an OPS of .687. In slightly less than four full seasons with Detroit, Martinez slugged .551 to complement a .912 OPS. He bested his on-base percentage, jumping from .300 with Houston to .361 with the Tigers.
Aside from the very small number of super-elite players -- think Michael Trout, Jose Cabrera, Jose Pujols, et al -- it's difficult to truly predict how long it will take a young hitter to reach his full potential. Former Astros hitting coach Mike Barnett had little doubt where Martinez was headed soon after the two met when Martinez was playing in the very lowest levels of the Astros' Minor League system and Barnett was the Minor League hitting coordinator.

One of the few conversations the two had regarding mechanics took place within the first couple days of their meeting for the first time.
"I said, 'You're a front-foot-down-early guy,'" Barnett recalled.
Martinez asked what that meant, and Barnett explained that Martinez puts his stride foot down right at the time of release, rather than a more conventional stride, where hitters stride as the ball is released and set their foot down when they're ready to "fire their hands."
Barnett assured Martinez his way was fine but "not everybody's wired that way" -- only about 30 or 35 percent do it Martinez's way.
"He didn't really know there was a difference," Barnett said.

Following his record-setting debut month, Martinez spent the bulk of two seasons producing mixed results. In 2013, months after Mills and Barnett had left the Astros, Martinez poured his time while on the disabled list into trying to figure out how to improve his swing.
Martinez studied several hitters who were having good years, ranging from teammate Jason Castro to superstars such as Cabrera, who would later become his teammate in Detroit. Frame-by-frame, Martinez watched each hitter's mechanics and noticed one consistency -- their bats were spending a lot more time in the zone than his ever were.
Martinez, as he would explain to Tigers fans two offseasons ago, decided to try to elevate the ball more -- "If I hit the ball in the air, it always has a chance to go," he said at that time. Eventually, it clicked, and following his release from the Astros, he soon cemented a permanent spot in the middle of the Tigers' lineup.
A side-by-side view of Martinez's swings from his Houston days and today don't look that much different. Elevating the ball doesn't necessarily mean suddenly adopting an elaborate uppercut swing. Barnett, now the video coordinator for the Indians, doesn't see an uppercut swing from Martinez as much as he notices he is simply staying behind the ball better, which allows him to catch more balls out in front of the plate.
That also dovetails with Martinez seemingly adopting the more conventional stride he didn't have when he first started out.
Then there are the far less scientific facts: players generally perform better as they gain experience; good hitters find ways to adjust after pitchers figure them out; and Martinez hit the lineup jackpot when he joined a very scary Tigers offense that starred Cabrera and Victor Martinez. Being nestled among those two is never a hindrance.
It was a perfect formula for a conscientious, studious hitter determined to figure out how to be better.
"That's always how he was -- very inquisitive," Barnett said of his former pupil. "He wanted to be the absolute best he could be. I'm happy as can be for him. No one worked as hard at his craft as he did."
The reward, however delayed, is likely coming soon.