Sure 31 points should be enough to win. Sure, the Defense and ST's were awful in the second half. Personally, I think that the Defense in the first half was amazingly good given who was on the field. They couldn't hold on after BUF made adjustments. We even had to play Woods for a few plays.
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HOWEVER, sometimes, an Offense is in a high scoring game where they PRAY to have the ball last with almost 2 minutes to go.
In the playoffs, that is what a team sometimes needs, no matter what happened earlier in the game. A high-level QB and a high-level Offense scores the TD and tries not to leave time on the clock for the other team. In the old days, we would have EXPECTED our team to score leaving no time left, not wanting to give Allen the ball again. If the roles were reversed and BUF were 4 points behind, their fans would have expected their team to win the game. Ditto for the LAR.