There are too many layers to the trade that sent Ian Kinsler to the Detroit Tigers and Prince Fielder to the Texas Rangers to write a single, coherent article in summary. Therefore, I’m breaking it up. I wrote about Kinsler’s complicated aging profile and skill set here.

For now, let’s delve into a critical question about Fielder, one that will determine whether the Rangers got much better on Wednesday or not: Is his power coming back?

Prince Fielder, Batted-Ball Distribution, 2011

Prince Fielder, Batted-Ball Distribution, 2012

Prince Fielder, Batted-Ball Distribution, 2013

Source: FanGraphs

He hit 38 total home runs in 2011, 30 in 2012 and 25 in 2013. His isolated power dropped from .267 to .215 to .178. As you can see, the bulk of that was the loss of opposite-field and center-field power. He also popped the ball up more, so it was not merely bad luck that stole homers from him, but certainly, the transition from Miller Park (2011, with very hitter-friendly center and left-center fields) to Comerica Park (which sternly punishes power to those spots) hurt him.

Rangers Ballpark in Arlington plays closer to Milwaukee than Detroit. It’s warmer, on average, and the fences are closer in those critical spots where Fielder lost many bombs over the past two seasons. I do think he’ll see some rebound in his power, which should help straighten out some of his other offensive issues.

On the other hand, there’s a physical, mechanical reason for Fielder’s fading pop, one that no ballpark switch can solve. He’s under six feet tall, and his swing is an uppercut that carries the bat through the hitting zone pretty level, really. This came up during a prolonged Fielder slump, during one of his last two seasons in Milwaukee. I remember a former player—it may have been Aaron Boone or Nomar Garciaparra, or neither—talking about Fielder’s issues, and comparing him with then-teammate Ryan Braun. The analyst pointed out, and demonstrated with video, that when Fielder chased pitches (especially fastballs) up in the zone, or out of it, the ball often got above his hands at the point of contact. When that happens, the ball goes straight up. That feeds Fielder’s pop-up problem. Being short, though, and given his swing mechanics, it’s a tough thing to fix, especially as Fielder’s bat slows down with age. You can see, although I don’t want to put too much specific trust in the numbers, that his bat is slowing down, from the way his directional distribution has drifted around toward left field over the last few years.

Going forward, then, maybe the most important thing for Fielder to be able to do is to take more pitches, especially those up in the zone. His strikeout and walk rates each degraded in 2013, not alarmingly, but noticeably. He needs to turn that around, because while he has very good power, he’s not off the charts in terms of homers per fly ball. Good plate discipline will be his ticket to retaining his offensive value into his mid-30s.