Actually, yes, Seymour has usually had a huge impact on Colts/Pats games. The problem is that you're essentially demanding that a DE personally manufacture victories as a proof when the only positions that are really capable of having that specifically demonstrated are QB, K and returners (and RB to a lesser extent). Great players at the other positions show their impact by improving the overall efficiency of the offense or defense. Seymour collapses the pocket against the pass, preventing the QB from stepping up, and he helps shut down the run. That's a huge impact in a game, as we were able to note by its absence this season. As was discussed on another thread, the Patriots gave up more 300 yards games this season than they had in the previous 2 years combined. This is with a defensive backfield that the vast majority of people would insist was better this year than last, and with TBC getting to the QB more than any linebacker did last year.