I'm going to start this article by posting Mark Trumbo's entire career stat box, minors included, and then point out something very interesting. (via Baseball Reference)
After being selected in the 18th round by the Angels in 2004, Trumbo began his steady climb through the minors in 2005 at Rookie level ball. He finished the season with a very solid line as a 19 year old, but upon moving to A ball, his numbers suffered. Not terribly concerning for the Angels, considering he wasn't exactly a touted prospect coming out of the 18th round. However, his trend throughout the rest of his minor league career would make any scout giddy.
Following his drop-off from Rookie to A ball, Trumbo's numbers improved on a yearly basis, even with increasing levels of competition. His average steadily climbed to over .300 in his final minor league season in 2010, and although his strikeout numbers remained relatively consistent, he steadily improved his OBP and showed that he can exhibit major league caliber plate discipline. His power rose as well, with the only outlier being a lackluster 15 homerun season in AA in 2009.
At the major league level, he is carrying a very similar trend. Following a near Rookie of the Year campaign in 2011 (falling to an absolutely brilliant season from the Ray's Jeremy Hellickson), Trumbo again improved his game in a number of areas. His average rose to a respectable .268 (from .254 in '11), he improved his AB/HR from 18.6 to 17, and marginally improved his abysmal BB/K rate and BB%. In 2013, Trumbo does not appear to be slowing his upward trend. He currently owns a .273/.341/.507 slash line, a 1.5 total WAR (2.1 in '11, 2.2 in '12), and has again increased his BB/K. Although his AB/HR has fallen to 18.5, he is still on pace to hit 35 homeruns, which would be a career high.
The bottom line here is that the sky is the limit for this kid, and at the age of 27, his best years may well be ahead of him.
On a sort-of related topic, Trumbo's homeruns travel. He currently owns the longest homerun of the season (according to ESPN HitTracker) for his 475 foot moonshot off of Dan Straily back on April 29th at the Coliseum. The ball came off the bat at 120.1 MPH, which is fast enough to kill a small animal. Trumbo's 11 homeruns this season have travelled an average distance of 414.5 feet, which interestingly enough, is practically identical to the average for his 32 bombs last year, which was 414.7 feet.
This kid can certainly hit the ball a ton, and it will be exciting to see what he has in store the next few years. If he can continue to improve his plate discipline, he could be one of the better hitters in the game.
Here is a GIF of Mark Trumbo making sure he doesn't shatter his femur on a walk-off homer.