Werth OPS+
2007 - 120
2008 - 122
2009 - 129
2010 - 144
2011 - 97
2012 - 125
Except for 2010 and 2011, he's been between 20% and 29% better than league average. He's still squarely in that range. Not only not washed up when he signed, he's still not showing too many signs of being washed up. Defense slipped last year but we'll see if that was blip or the start of a trend.
http://www.baseball-reference.com/players/w/werthja01.shtml
Poll
