The strength of schedule for receivers lumps wide receivers and tight ends together since each team uses the positions differently. While overall averages are interesting, no position is as sensitive to individual matchups as are receivers facing particular defensive backs. This makes the analysis less accurate than that for running backs and quarterbacks. The best receiver for an offense invariably draws the best coverage defender, if not more than one on most plays.
The analysis also considers the venue. There is a difference between how defenses respond either home or away, and that creates 64 “different defensive matchups” depending on where the game is played.
