TEMPE, Ariz. -- It's hard to say exactly where power comes from. It's even harder to say how two players of similar stock can travel such divergent paths with the same raw material.
We're talking about the kind of raw, light-tower power that front-office executives can't get enough of and managers beg for in the middle of the lineup.
It's the most valuable skill a baseball player can have, and the least predictable. A player can blast 35 home runs in Double-A but struggle to make contact in Triple-A.
Or worse, a player such as Los Angeles Angels third baseman Brandon Wood can average 28.2 home runs over his past five full seasons in the minors and seem like a sure thing then inexplicably bomb when he's finally given a chance to play regularly in the majors.
Wood and the Angels spent countless hours in the winter assessing what went wrong, as he hit .146 with four home runs and 14 RBIs in 81 games last year. They've studied video tape of his at-bats, worked on adjustments in the batting cages and even worked in 75-80 extra at-bats in the Arizona fall league.
But the question remains: Why didn't his power and performance translate from the minor leagues to the majors?
The Angels are thinking hard on that as they weigh whether to cut their losses with Wood, who is out of minor league options, or give him another chance.
All of that has become important this spring, as Mark Trumbo, the next great power hitter to come up through the Angels' system, seems to have played his way into a roster spot by hitting. .340 with five home runs and 13 RBIs.
In their finest moments, it is hard to tell the difference between the two young sluggers. After all, home runs are home runs, and Wood (161 HRs/eight minor league seasons) and Trumbo (120 HRs/six seasons) have smacked a bunch of them.
Their batting averages (.284 for Wood, .275 for Trumbo) are nearly identical. Wood, 26, is exactly 10 months, 2 weeks older than Trumbo, 25.
How then to tell them apart? To predict whether Trumbo will succeed where Wood has fallen short? Or even to make an educated guess on whether Wood has the ability to resurrect his career after last year went so wrong?
The simple answer is you really can't answer that. The better answer is you still have to try.
"You never know, when you move a player up, how he's going to respond," Angels manager Mike Scioscia said. "Everybody is an individual.
"But there are some statistical analyses you can make, as well as some scouting analyses from the coaches and managers that have been with him every year."
A couple years ago, the Angels started evaluating how their top prospects fared against the best 15-20 pitchers in whichever league they were in. They wanted to determine whether a player was simply feasting on lesser pitching or seemed to elevate his game against the best competition.
It is one tool the team uses in evaluating its prospects, but in the case of Wood and Trumbo the results are interesting.
Year after year, Trumbo was "consistently good" against the top pitchers in his league, according to Tory Hernandez, the Angels director of baseball operations. While Wood was never bad but he "hasn't been great," either.
"It's not concrete, nor does it give us an exact barometer as to how [a player] is going to perform," Hernandez said. "But it certainly gives us what we think is one indicator as to how he could perform in the major leagues."
The question the Angels are wrestling with is whether Wood simply needs another season or two to make adjustments, like some of this generation's best power hitters, such as Paul Konerko and Jayson Werth.
"It's all about tools," Hernandez said. "You have to have tools in order to be successful in this game, and Brandon's tools are so much better than most people.
"Yes, he has struggled, those tools haven't translated to games yet, but he's still a young man. He's still going to get opportunities, because there's still something in there."
Wood spent the offseason working on his mechanics and said he's identified an area for improvement he believes will make a huge difference if he's given another chance to be the Angels' everyday third baseman again.
"It was about putting myself in a better position to hit, not pulling off the ball and using my lower half," he said. "That was the biggest thing.
"I'm doing that in the cage really well; I'm doing it in batting practice. And I have spurts in spring training where I'm doing it in the games, but it's going to take a little more time to where it can be just second nature in a game."
There is no way to predict whether Trumbo will need the same adjustment period Wood has.
There is everything to like about Trumbo. His attitude is exactly what you'd hope for in a young player waiting for his shot: humble yet confident and competitive. He's built like a young Mark McGwire, can play first base and a corner outfield spot, can hit for power and average and seems to have improved at every level on his progression through the minor leagues.
A lot of those things could also have been said about Wood last year, but comparing him to Wood seems to be the only line of questioning Trumbo mildly bristles at.
"You have to have your own confidence in yourself," Trumbo said, "and not listen to anyone else's track record because you're your own player and it's up to you to get the job done."
Unlike Wood, whose career neatly progressed year to year after the Angels picked him in the first round of the 2003 draft, Trumbo has already experienced and learned from major setbacks.
The first part of his minor league career took a bit longer than anyone expected. He even had to repeat low-Class A ball after batting .220 in the Midwest League in 2006.
"You never want to have happen," Hernandez said. "But he was young enough that it wasn't detrimental to his career. Actually, it was probably a huge learning lesson for him, because he's progressively gotten better from that year. … And now you see him this spring, he's facing the best pitching he's ever faced and he's performing even better than he did last year."
When the Angels drafted Trumbo in the 18th round of the 2004 draft (where he'd fallen because of concerns related to his commitment to USC), they saw him as a potentially great power hitter. They gave him a signing bonus commensurate with a late-first-round or early-supplemental-round pick.
They gave it to him because he has one of baseball's most valuable and volatile raw materials.
"He has that Roy Hobbs, light-tower power," Hernandez said. "When he connects, he has so much bat speed and strength; they're moon-tower shots.
"It's something you don't see very often."
The Angels see it twice a day.
The only thing worse than having too much of a good thing is not getting enough out of it.
Ramona Shelburne is a columnist and writer for ESPNLosAngeles.com. Follow her on Twitter.