Matt Wieters came into the 2010 season with some people considering him a disappointment. The guy who was supposed to be "Mauer With Power" and demolished the minor leagues was just a .266/.328/.393 career hitter. Many of the raw tools were still there, but we hadn't seen them put to use in games consistently.
Here are by pre-season projections for Wieters, compared with how things shook out:
I said I wouldn't trust the home run output to go up until it actually started to happen - and it did indeed start to happen. Wieters' home run per flyball rate jumped from the 8-8.5% range to 13.6%, allowing him to more than double his career home run out put (he had 20 in 2009-10 combined) while actually keeping the same batted-ball profile (it wasn't a case of elevating the ball more).
There were a couple of big changes with the home runs. One was their location. In 2010, Wieters had 502 plate appearances and ended up hitting 10 home runs to left and right field (combined). In 2011, Wieters had 551 plate appearances and ended up hitting 13 home runs to left and right field (combined). The difference was, in '10 only one ball went out to center (and it was about as left-center as you can get and still be in the middle third of the diamond), while in '11 there were 9 balls that went out to center (one of which was also right on the left/center line, but the other 8 were not). It's nice to see Wieters being able to go yard to the deepest part of the park.
Additionally, there was a huge reversal in his platoon numbers. Here are his percent of plate appearances ending with a home run from each side of the plate:
You can see that his power production from the left side stayed pretty much constant. From the right side though, he began to crush the ball. Wieters had been stronger against righties in his career, coming into 2011 - .335 wOBA from the left side, .275 wOBA from the right side - but that flipped around this season (and how!). A pedestrian .290 wOBA against righties that might have made the season look bad was saved by an almost Bondsian .472 wOBA against lefties. He walked in over 14% of his plate appearances against south-paws, and took them deep 11 times in only 142 PA. In fact, the only player in the majors to hit better versus lefties than Wieters was Jose Bautista (who crushed everyone).
The question is, will this persist (obviously it won't to this degree, but will it at all)? If something changed permanently for Wieters from the right side, and he bounces back from the left side, then he can certainly keep his overall production going at 2011 levels. If this was a fluke occurrence though (and the .380 BABIP and 25% HR/FB rate as a lefty in a relatively small sample of at bats indicate that it might be), then Wieters might not progressing quite as much as it appears.
Looking beyond the home run output, things didn't change much in the aggregate. Wieters' walk rate fell from 9.4% to 8.7%, but his unintentional walk rate went from 8% to 8.2% (he effectively walked one more time than in 2010). His strike-out rate fell from 18.7% to 15.2%, but because his BABIP also dropped once again (from .287 to .276), there wasn't much of a positive effect on his batting average there. Improving the plate discipline would really be a plus, as Wieters still expands the zone sometimes (though he's gotten better at actually going after strikes).
A 110 wRC+ from a catcher is mighty fine though, especially when he's so good behind the plate. There were 0 wild pitches on his watch, and only 1 passed ball allowed (tied for the fewest in the majors, but Wieters caught more innings than the other guys with 1). He nabbed 37% of opposing base-stealers - the second highest mark in baseball. The advanced metrics love him; Defensive Runs Saved had Wieters as catcher in baseball at +14 runs, with +5 runs on stolen bases (#2); Total Zone had him second at +10 runs; and based on some research by Mike Fast, it appears that Wieters might also save some runs with his pitch-framing. While in the past I've often been one to try to head off the home-town fans clamoring for an Oriole to win a Gold Glove (Jones, Markakis), I think that Wieters is more than deserving - and there's a good chance it'll happen (I think appreciation for his defense is partly why he was chosen for the All-Star team this year).
The offense plus the defense made Wieters around a 4-5 win player this past season - that makes him the team MVP in my book, and should hopefully quiet many of his (unfair) critics. Hopefully he can build on his 2011 success going forward.