Last year, Patriots wide receiver Wes Welker emerged as the perfect complement to Randy Moss. When teams devoted safeties to double up on Moss, Welker abused linebackers and nickel backs in the slot to the tune of an NFL-high 112 catches. The undrafted Texas Tech grad was widely regarded as an important part of the best offense in league history. The most fascinating aspect of Welker's season, though, wasn't how many passes he caught or where he came from; it was how successful he was at actually catching the ball.
While we often think of completion percentage when looking at the ability of a quarterback, it's rarely used when analyzing the performance of a wide receiver. Heaping all of the credit for a completed pass and the blame for an incomplete one on the quarterback is obviously inaccurate; both the quarterback and his receiver have a role to play. From 1995 through 2007, quarterbacks who threw more than 250 passes in a season averaged a completion percentage of 59.2 percent. Over that same timeframe, wide receivers who had 50 or more passes thrown to them in a given season had an average catch rate of 55.4 percent.
When you compare Welker to similar players, though, he still shines. Welker averaged 10.5 yards per reception last year. If we look at all receivers since 1995 who averaged less than 11 yards per reception, the average catch rate was 58 percent. That's above the league-wide average of 55 percent, but still significantly below Welker's astounding figure of 77 percent.
Welker also clearly benefited from having Tom Brady behind center. In 2006, Welker toiled for the Miami Dolphins and caught "only" 67 percent of the passes thrown to him; still an above-average figure, but nowhere near what he did in 2007.
However, Welker is an exception, because usually changing teams has surprisingly little effect on a receiver's catch rate. Exactly 120 receivers besides Welker had 50 attempts thrown to them in consecutive seasons for different teams (since 1995). Sixty-one of them saw their catch rate decline, and 59 saw it improve. The average change was -0.5 percent; in other words, basically nothing. There's no doubt that Brady helped Welker (especially when you consider that Moss saw his catch rate rise by 18 percent), but the way Welker was used and his own innate ability to catch the ball played a huge factor as well.
Even with Brady as quarterback, nobody would have predicted before 2007 that Welker would have improved on his previous catch rate of 67 percent. Since 1995, 68 wide receivers have caught between 65 percent and 70 percent of the 50-plus passes thrown to them in a season. Only 15 receivers (22 percent ) saw their catch rate rise the next season, and only Welker saw his rise more than 7.5 percent. All in all, those receivers saw an average drop of nearly -5.6 percent in catch rate the year after; Welker's performance simply blew that away.
Simple regression would project a decreased catch rate for Welker in 2008. Receivers who caught 70 percent of the passes thrown to them in a season saw their catch rate decline, on average, by 10.2 percent the year after. If he's to put up another year like his 2007, Wes Welker will have to defy expectations yet again.
Bill Barnwell is a contributing editor to FootballOutsiders.com and co-author of the book Pro Football Prospectus 2008, in stores now.