If Sewel is such a "bad bass blocker" then why is his overall grade, by the same entity, so high? Derp
If ESPN graded the bears O-line as such a good pass blocking unit, why did the Bears allow the most sacks in the league? Derp
Why does Patrick only grade out marginally better than Mustipher? Derp
No idea why you are so confused by this. If his pass blocking is lower than his overall grade then it obviously means his run blocking grade is higher. He had a 69.4 pass block grade and an 84.5 run block grade. His overall grade is in between at 77 which one would expect if one understands Math.
The Bears led the league in sacks because Fields held the ball on average 3.09 seconds and on average it took 3.57seconds to sack him. The Bears being 6th in PBWR is based on them holding blocks for 2.5 seconds. Do I really need to explain Math again. He was holding the ball on average a full second longer than the 2.5 seconds PBWR is based on.
Finally Patrick only grades out marginally better than Mustipher because PFF thinks he is only a marginally better player. Duh. My only comment to you was that you can't celebrate PFF when it shits on Patrick but then cry about it when it shits on Sewell. The fact is Patrick and Sewell's pass blocking grades were similar ie 69.4 vs 64.3. So again if you going to tout PFF then both are below average pass blockers. Sewell is just an exceptional run blocker.
Hopefully this clears things up for you as if you still dont get it then may need my 12 year old nephew to respond so you can converse with someone at your level.