CLEVELAND -- There really is no offseason for Trevor Bauer. There is a period of time on the calendar that does not include games, but the pitcher never stops working. For Bauer, baseball is indeed a science, and he is never done studying the physics and theories behind his craft.
Since Bauer came to Cleveland in a blockbuster trade four years ago, he has treated himself as a project. Overhauling his delivery -- or rewriting his neuromuscular programming, as he once phrased it -- took several years. Once he found a comfort level there, Bauer was better able to tackle his approach, pitch usage and velocity training. It has all led to this: Starting against the Red Sox in Game 1 of the American League Division Series (Thursday on TBS, 8 p.m. ET).
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"I really value my job as a starter. That's what I've trained for my entire life," Bauer said. "Literally, my entire life, that's what I've trained to do. I don't remember a time when I didn't want to be a starter in the big leagues. And when I train, there's certain things I do, certain sacrifices that I make to make sure that I'm durable and that I'm healthy and that I can be a starter."
Bauer does not consider himself a finished product, but the right-hander does feel like he is in a great spot, both physically and mentally, as his Game 1 assignment looms. Given Cleveland's starting setbacks of late, Bauer may just be the key to October success for the team. Injuries robbed the Indians of having Carlos Carrasco and Danny Salazar in the postseason rotation. A minor leg issue pushed ace Corey Kluber back to Game 2.
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Through all the problems, Bauer has continued to climb up the rotation ladder, showing that his unique training regimen is paying off. Pitching coach Mickey Callaway joked that the righty has "a rubber arm," and that could be put to the test if the club needs Bauer to pitch on three days' rest in a potential Game 4 at Fenway Park.
"Hopefully, the groundwork I've laid in the past offseason," Bauer said, "and in the past couple years, all the way back to when I began pro ball and changed my mechanics, is paying dividends now. ... I'm perfectly healthy, my arm feels great, my body feels great at his point in the year. I feel fresh. A lot of that is stuff people wouldn't necessarily see, but that's all because of the way I train."
Callaway believes Bauer is ready for the challenge ahead.
"Each year, he's gotten better and better," Callaway said. "This year, the way he uses information, applies it in the game has been better. His approach, his work, has been more consistent game to game. The way he's handling adversity has been a lot better. There's not as many ups and downs throughout the season as we've seen in the past. And he's becoming more even-keeled."
Bauer flips fastballs
One of the things that defines Bauer as a pitcher now was practically non-existent just three seasons ago.
Over the course of the 2014-16 campaigns, Bauer has gradually switched from using his four-seamer as his main fastball to featuring his two-seamer more often. Do not call the pitch a sinker, either. Bauer refers to his fastball as a "true two-seamer" due to its lateral movement. When it is working best, it begins in on a left-hander batter and zips back over the insider corner. Or if the pitch is operating properly, Bauer can freeze a right-handed hitter with an outside strike that looked like it was going to be off the plate.

In the offseason prior to last year, Bauer broke down film of the two-seamer used by Blue Jays righty Marcus Stroman, who can "backdoor" the pitch to righties effectively. This season, Bauer used his two-seamer 29.1 percent of the time -- up from 12.4 percent last year. Back in 2014, Bauer used the two-seamer less than one percent of the time, but threw a four-seamer at a 49.7 percent rate. It is down to 21.9 percent this year.
Beyond those two fastballs, Bauer also has a cutter that he has worked extensively on over the past few years. Last year, the movement and velocity of the offering actually resulted in it registering as a slider at times by PITCHf/x. The righty went to work on increasing its velocity this past winter, and has seen that pitch climb by a few mph. His four-seamer is also up by about one mph over 2015.
No trouble with the curve
Another improvement this season has come within Bauer's breaking ball.
According to Fangraphs, Bauer's curveball had a pitch value of 8.3 this season, making it the fifth-best curve in baseball. Only Kluber, Kansas City's Yordano Ventura, San Francisco's Madison Bumgarner and Detroit's Justin Verlander had curves that rated better. Among pitchers who had at least 100 at-bats end with a curve, Bauer ranked third in opponents' batting average (.132), behind Kluber (.108) and Bumgarner (.130).
In previous years, Bauer would mainly fire his curveball in the dirt, especially when ahead in the count. That allowed for situations in which batters would eliminate that pitch from their thinking, which better enabled them to sit on the fastball. This season, Bauer has trusted his ability to fire the curveball inside the strike zone more often, and that has led to an increase in called strikes (he ranked sixth in the Majors with 17 called strikeouts with his curve).

Catcher Chris Gimenez said one of the keys to making Bauer's pitches more effective -- especially the curve and changeup -- is to try to throw them harder. The arm action then looks similar from pitch to pitch and, considering Bauer often elevates his fastball intentionally, a curveball that begins high but breaks to the lower third of the strike zone can lead to more frozen hitters.
One matchup to watch during Game 1 of the ALDS will be Red Sox slugger David Ortiz against Bauer. While Bauer has excelled at curveballs low in the zone to left-handed hitters, Ortiz has had a knack for attacking that very pitch. Ortiz posted a .500 slugging percentage this season on curves in the lower third of the zone, or below the zone. Bauer, on the other hand, allowed just a .194 slugging percentage on curves to the same regions.