Anquan Boldin, approaching 35, among underrated wide receivers

AP Photo/Bill Haber

Many wide receivers in the NFL have a defined role in their offense that has a direct impact on the quality of statistics they produce. This can make comparing useful numbers like catch rate and yards after catch (YAC) difficult when looking at a slot receiver (such as Percy Harvin) versus a deep threat (such as Malcom Floyd).

Receiver A catches 65 percent of his targets and averages 6.0 YAC. Receiver B catches 58 percent of his targets and averages 4.2 YAC.

Is Receiver A better than Receiver B? Not necessarily, if Receiver A is catching his passes much closer to the line of scrimmage: shorter throws are completed at a higher rate and lead to more YAC. Where the player catches the ball is very important in analyzing performance. The quality of the quarterback also has a significant impact on a receiver.

This is why Football Outsiders uses two similar metrics that incorporate game charting to add context to a receiver's performance: plus-minus and YAC+.

Plus-minus estimates how many passes a receiver caught compared to what an average receiver would have caught, given the location of those passes. It does not consider passes thrown away on purpose or batted down at the line. Player performance is compared to a historical baseline of how often a pass is caught based on the pass distance, the distance required for a first down, and whether the pass is outside or in the middle of the field. Note that plus-minus is not scaled to a player's target total.

Plus-minus says a lot about the quarterback's accuracy, since the stat is based on the throw. YAC+ is much more about the receiver's ability to create yards after the catch.

YAC+ estimates how many YAC a receiver gained compared to what we would have expected from an average receiver catching passes of similar length in similar down-and-distance situations. This is imperfect -- we don't specifically mark what route a player runs, and obviously a go route will have more YAC than a comeback -- but it does a fairly good job of telling you if this receiver gets more or less YAC than other receivers with similar usage patterns. Unlike regular YAC numbers, YAC+ does not penalize players who catch a lot of passes at or near the goal line where there are no (or very few) yards after catch available.

We have these stats for every season since 2006, but the focus here is on the last three years as we look for wide receivers with notable performances in these metrics, keeping the quality of their quarterbacks in mind. The following is a look at five receivers who have exceeded expectations.

For five overrated wide receivers, click here.

Note: Rankings for the 2012-14 period include 70 wide receivers with at least 100 receptions over the course of those three years. References to single-season rankings are for wide receivers with at least 50 receptions in that year.

Anquan Boldin, San Francisco 49ers

Plus-minus (2012-14): plus-13.5 (15th)

YAC+ (2012-14): plus-0.3 (21st)

Whether winning 50/50 balls from Joe Flacco or snatching off-target throws from Colin Kaepernick, Boldin has continued to excel in his early thirties. He is coming off his seventh 1,000-yard season and looks to remain a No. 1 receiver in San Francisco even as he approaches the age of 35.