Fields played on one leg and was basically a statue out there. Even with that liability tO$U shredded UW's defense from the last drive of the 1st half on.
If you watched UW's defense from the 2nd quarter on they ignored Fields' running ability. That meant that could run all out at him and ignore him his run options.
He literally could have hopped on one leg for 30 yards at anytime if they let him.