The situation is this: Saturday, September 7th, bottom of the 10th inning, the Orioles are losing to the White Sox 3-2 at home. Conor Gillaspie had put the Sox ahead with a blast off of Tommy Hunter, and all closer Addison Reed has to do is set down the O's in the bottom half to seal the win.
The first batter up, J.J. Hardy, grounds out. One down. Next, pinch hitter Henry Urrutia punches a single to the left side. Chris Dickerson pinch runs for him. Then Nick Markakis steps to the plate and singles, moving Dickerson to third. Things are looking interesting now, but Nate McLouth strikes out looking, although Markakis steals second base.
With two on and two out, Matt Wieters works the count to 2-1. On the next pitch he singles to right field, bringing both runners home and transforming a likely loss into a 4-3 victory. Walkoff. Pandemonium. Chaos.
In terms of how much it added to the team's probability of winning, that hit was the second-most valuable plate appearance in the O's entire season. I'm sure Wieters savored it, because he didn't have much else to celebrate this year. Going into the season, expectations were high following his solid 2011-2012 seasons when he hit a combined .255/.328/.443 (108 wRC+) with 45 HR, helped himself to 8.5 fWAR, and made two straight All Star teams. (Heck, he even got a few MVP votes in 2012.) After all, 2013 would be his age-27 season, and players typically peak around that time. And this offense is on top of his stellar, Gold Glove defense.
The Orioles must have been excited, because they gave him an 11x raise in his first year of arbitration. Instead, Wieters took a step backwards, hitting just .235/.287/.417 (86 wRC+). Although he bopped 22 dingers, that wRC+ (which is low to begin with) ranks him sixth out of the six qualified AL catchers. If you add in his defense and baserunning, you get 2.4 fWAR, ranked fourth out of six. That's still plenty good enough to play every day, but it left a lot of fans wondering what happened to the Switch-Hitting Jesus they were promised in 2009.
His poor season started and ended with a tremendous amount of bad luck. His batting average on balls in play (BABIP) was .247. Not only was that the third-lowest among all qualified hitters, it was about 13% below his career average. That is a huge year-to-year-drop, too big to be explained solely by a decline in skill. Every season a couple of players are going to hit a ton of liners right at guys; this year, Wieters was one of them. His luck started terribly and didn't improve much throughout the season.
But I don't think luck was the whole story. There's evidence that he added to his own woes by chasing bad pitches. Evidence of a changed approach at the plate shows up in his batted ball profile. Wieters normally hits more grounders than fly balls in a season; this year, he reversed that split by quite a large amount. That says to me that he was trying to uppercut the ball.
He also swung more frequently than he normally does, but he actually made contact less frequently on pitches inside the zone. He did, however, make contact on 5% more pitches outside the zone than he usually does. This poor contact likely contributed to a 3% rise in infield fly balls (vs. his average season). An infield fly is about the worst kind of ball you can hit, even worse than a ground ball. I don't have the numbers available, but I'd bet that Wieters' contact rate on bad pitches rose throughout the year as he pressed at the plate to make up for previous failures.
What's in store for Wieters in 2014? We all know he isn't going anywhere (nor should he). It's his second year of arbitration, so he'll probably get a raise. If Dan Duquette were shrewd, he might try to sign Wieters long-term now, using this bad season as leverage to get a cheaper contract than he could've before the season started.
But no matter his salary, his BABIP is likely to regress to the mean, which will improve his offense. The Steamer projections have Wieters at a respectable .252/.321/.431 performance for next year, mostly on the logic that his BABIP will rise by about 30 points. It's a safe bet to take, considering we have over four seasons of data on how Wieters performs and that he's still in his prime.
However, if he continues his poor (perhaps even misguided) approach at the plate, regression will not help him as much, and he will underperform again next year. This is one case where doing nothing is likely to pay off.