GOODYEAR, Ariz. -- We tend to think about Jay Bruce, at this point, as settled law.

Bruce broke in with the Reds back in 2008, and immediately established himself as a power threat and strong defensive right fielder. The past three years, he's seen that power jump from mid-20s homers to 30-plus each of the past three years. In a game where power is increasingly rare, Bruce is a valuable commodity indeed, consistently hitting home runs and staying on the field.

Over the past three seasons, only three players have more home runs than Jay Bruce: Miguel Cabrera, Jose Bautista and Adrian Beltre. (We covered the whole Beltre is criminally underappreciated thing here.)

That's it. Not Giancarlo Stanton. Not Prince Fielder. Not Albert Pujols or David Ortiz.

But beneath this number are indicators that Bruce is a player with significant variability at this point -- not surprising for a guy who won't be 27 until next month.

Some of his teammates may get more attention, with a Reds official telling me requests for Votto, Brandon Phillips and, this year, Billy Hamilton dwarf Bruce's media requests. Yet Bruce reaching another level could be the biggest driver for Cincinnati's 2014 season and beyond.

One thing that lifted Bruce's 2013 season was his defensive performance. It's difficult to peg Bruce's defensive value, and it wouldn't be surprising to see his raw number of balls reached drop with Billy Hamilton rather than Shin-Soo Choo next to him. But, while defensive metrics can vary widely from year to year, his UZR/150 of 10.1 was his best number since 2010.

For his part, Bruce said he doesn't worry much about his UZR, but definitely felt the season he had dovetailed with what it described.

"It's really just trying to focus on being the best, just getting the most out of my ability," Bruce said in front of his locker in Goodyear. "Being prepared, being in the game. Not that I wasn't over the years before, but just making sure I do everything I can to be prepared to make those plays."

But while Bruce is a fairly settled product in the field -- he hasn't altered anything in his routine -- there's a ton of work going on as he continues to figure out just what kind of hitter he wants to be.

Consider that even though his home runs stayed steady, with 32, 34 and 30 over the past three seasons, they've been doing so while his fly ball rate continues to fall, from 46.7 percent of his batted balls in 2011 to 39.4 percent in 2013. This would be more alarming if, for one thing, it wasn't part of a deliberate plan. For another, he's trading all of those fly balls for line drives. His ground ball rate has remained steady. And his line drives are up, from 16.8 percent in 2011 to 23.9 percent in 2013.

It's the kind of thing that you'd figure would give his batting average a boost. So far, that hasn't happened. But Bruce believes it can, and will.

"I don't do it to create a higher line drive percentage," Bruce said. "But I do believe, the more line drives you hit, the more opportunities you're going to have to not get out. And that's kind of the name of the game."

Bruce says much of what he does is cage work, around 40 pitches seen per day, with different drills to help him prepare for this effort in the game.

"I do a lot of one-handed drills," Bruce said. "Anything that helps me focus on swing plane."

But what's interesting about Bruce's line-drive approach is how targeted it's been on his at-bats against right-handed pitching. Last year, against righties, Bruce had a line drive rate of nearly 26 percent. Against lefties, it was less than 20 percent. The results, when he'd frequently sell out for power, were predictable.

Bruce has reached double figures in home runs each of the past four years against lefties, and actually has the most home runs of any player over the last four years against left-handed pitching. But he's paid the price for focusing so much on power against lefties, with a diminishing season OPS.

Bruce wants to take the approach to lefties this year he has to righties. And his manager, Bryan Price, likes what he's seen so far. He'd certainly be in a position to evaluate that effort, as a former left-handed pitcher himself.

"I think that he's made a great effort," Price said during an interview in his office. "He hits off of me a lot. He had a really nice at-bat the other day against Robbie Ross, shot a ball to left-center. I think he's made a real commitment to hang in on lefties better, not to sell out so much on trying to pull. And he's been terrific.

"So he's making a concerted effort, not just against left-handed pitching, to stay in the middle of the diamond and be a gap-to-gap power guy. And that's been a concerted effort for sure. He really wants to be an outstanding hitter, not just a home run hitter."

An interesting by-product of this approach against lefties so far this spring has been a jump in his walk rate. With the caveat that this is both an incredibly small sample and a spring one, Bruce is walking roughly twice as often as he did last year. And considering the number of swings and misses Bruce produced on off-speed pitches from lefties, it is easy to posit why that would be happening.

"My focus isn't walking," Bruce said. "My focus is to be able to get the outcome that I want, which is damage, the extra-base hit. And I think the walks may be a product of not swinging at the pitches I don't have success against. What I've been focused on this spring training is really turning the counts to my favor."

Whether this success can continue into the regular season remains to be seen, of course. And it is worth keeping in mind that if Bruce does nothing more than continue doing what he's done through age 26, he'll be a huge asset to the Reds for years to come. Already, Bruce is 12th on the Reds' all-time list for home runs, and a typical Bruce season will lift him past Wally Post and Vada Pinson and close in on Barry Larkin and Eric Davis.

But to really get a sense of the crowd he's in, notice that through age 26, only three Reds have hit more home runs with the team: Adam Dunn, Johnny Bench and Frank Robinson.

"You know, I haven't thought a whole lot about it," Bruce said of his place in Reds history. "I think because when you're in it, when you're doing it, you don't think too much about it. I see the little stats here and there. I wouldn't even consider myself mentioned with those guys right now. But to have the opportunity to start so early, and hopefully to log a lot more years here, who knows what can happen? So I'm excited about that."