Strength of schedule is calculated from the opponents projected fantasy points allowed for the WR position. The best rating is +16 which gives the player the advantage against the defense and indicates an easy opponent, the worst rating is -16 which gives the defense the advantage and indicates a tough opponent.
He is playing a dangerous game bluffing to hold out the entire season. This situation becomes worse by the day. Crabtree has missed significant time and will be playing catch up the rest of the season. Still worth a late round flier but more attractive in keeper/dynasty leagues.