Weighted rankings are a way of measuring a team's 'true' performance, taking into account the relative strength of each opponent. For example, a team throwing for 300 yards against a team that gives up 250 yards on average, would have a weighted performance of +50 yards. Conversely, if the opponent ordinarily allows 350 yards against other opponents, then the team would have a weighted performance of -50 yards.
This chart shows not only the weighted performance in key areas of the game, but also the weighted performance of the corresponding unit of their opponent, eg: Run Offense vs Run Defense.