Strength of schedule is calculated from the opponents projected fantasy points allowed for the DB 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.
Woodson returned to where his NFL career began in the offseason, signing with the Raiders after being released by the Green Bay Packers. At 36 Woodson clearly isn't the player he once was, and durability has been an issue of late. However, it's worth bearing in mind that it wasn't that long ago (2011) that Woodson, who will start at FS in Oakland, was fantasy football's runner-up at defensive back.