Dan Campbell has made a lot of good decisions on 4th down, but late Sunday against the Vikings he made a costly error. Campbell elected to attempt a FG while up 3 points on 4th-and-4 at the Vikings' 36. Win probabilities from ESPN's model based on the decision: Go: 89.6% Kick: 85.4% Punt: 90.0% So the model slightly preferred punt as the best option over going for it. But it substantially preferred either over attempting the FG. The difference between being up 3 and 6 late is very small.
