Strength of schedule is calculated from the opponents projected fantasy points allowed for the DL 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.
Over the past few seasons Long has developed into a very steady pass rusher, racking up 33 sacks over the past three seasons. Unfortunately from a fantasy perspective, he's also failed to hit 40 tackles in those years, making him a very streaky IDP option. If you're counting on Chris long as a weekly fantasy starter, do it knowing that for every big week the 28-year-old puts up there's going to be a week where he disappears.