Opponent Rank Against Position: indicates the opponent's rank against the player's position, based upon total fantasy points scored. Therefore if a running back shows a OPRK value of 10, it means that the player's opponent has surrendered the 10th fewest fantasy points to other RBs. OPRK of 1 to 16 is shown in red to indicate a tough match-up. OPRK of 17-32 is in green, indicating a good match-up since the opponent is ranked in the bottom half of all teams against that position.