See PFF's "About" page for more information on their grading system.

Offense

Best: Andre Smith (+4.3)

Other good grades: Andrew Whitworth (+1.3), Kevin Zeitler (+1.0), BenJarvus Green-Ellis (+1.0), Trevor Robinson (+0.9)

Worst: Clint Boling (-3.5)

Other bad grades: A.J. Green (-2.3), Jermaine Gresham (-2.2; -1.9 run block), Kyle Cook (-1.2; -1.9 penalty)

Defense

Best: Geno Atkins (+8.5; +6.1 pass rush)

Other good grades: Domata Peko (+2.9; +3.1 pass rush), Nate Clements (+2.1 in 6 snaps), Reggie Nelson (+2.0), Wallace Gilberry (+1.5), Terence Newman (+1.3), Chris Crocker (+1.0)

Worst: Carlos Dunlap (-3.1)
Other bad grades: Pat Sims (-1.8; -1.2 run defense), Rey Maualuga (-1.6; -1.9 pass coverage), Leon Hall (-1.5), Vontaze Burfict (-0.9), Michael Johnson (-0.9; -1.6 run defense)

Other performances of note:

-The grades support the heartbreak: the Bengals cumulatively out-graded the Cowboys on offense (-2.1 to -10.7), defense (+10.5 to -3.8) and special teams (+4.5 to -2.4)

-Gresham's poor run block grade came mostly against Anthony Spencer, the Cowboys' highest graded defender (+4.3 for the game, +26.3 on the year).

-In their ReFocused write-up, the PFF folks suspect Boling was playing at <100% health, leading to his uncharacteristically poor play.

-In their Reaction Blog, PFF implies that Dunlap could have graded very well if it were not for two missed tackles of Romo.

-More Whitworth: A few weeks back I took a closer look at Andrew Whitworth's grades with the intention of better informing the "Whitworth isn't as good as he used to be" narrative that has persisted throughout the season. The conclusion then was: he continues to dominate as a pass blocker, but not so much any more as a run blocker.

There continues to be a steady stream of comments suggesting that folks* may have misinterpreted "no longer dominates" as equivalent to: "is terrible": "Whitworth is useless in the run game", "if it weren't for Boling, we'd never run left", etc., and that's not entirely fair. The reality: Whitworth is not worthless in run blocking, but merely slightly below average- his PFF run block grade is -1.2 cumulative on the year, which ranks 44 of 72 tackles that have played >25% of total snaps. And, of course, he is still the best pass blocker in the league (+21.8, ranked 1 of 72) .

-All this being said, Andre Smith has become the better overall tackle (+10.5 pass block, +9.8 run block), which has him ranked 4th in the league in overall grade (Whitworth is 10th). n.b.: This is due entirely to an improvement in Andre's performance rather than a decline in Whitworth's.

* folks who saw the analysis in the first place, of course