Here is what the tape tells you about this free-agent pass rush class, and why the number you see on the contract announcement is almost never the number that should determine your evaluation.

Edge rusher is the position where the production-to-tape gap is largest, consistently, every year. The reason is that sack totals are generated within defensive schemes, and schemes vary enough from one organization to another that the player who produces twelve sacks in one system and the player who produces four in another may be the same player with the same fundamental ability. The number tells you what happened. The tape tells you why.

What I look for on tape before I tell you any edge rusher is worth a dime in free agency: first, counter moves. The first move tells you about athleticism. The counter tells you about football intelligence. Every good edge rusher in the history of the game has at least two counters — a speed-to-power conversion and either a spin or a swim — and executes them off a read of the offensive tackle's initial set. If an edge rusher's production has come primarily off one move, he will be figured out within eighteen months of signing his new contract. I have seen it happen forty times.

Second: effort on run defense. The most honest diagnostic of an edge rusher's competitive character is how hard he works on plays where he is not the primary assignment. The flashy players who disappear in the run game are visible on tape if you know what to look for. They are also consistently disappointing in the second year of their contracts because the teams that run against them learn to run at them in year two.

Third: pass-rush efficiency rate, not sack totals. There is one edge rusher in this free-agent class who produced four sacks last season — below what the market typically rewards — and whose pressure rate on third downs was in the top six among all qualifying rushers. He was consistently one step away. His technique is cleaner than his production suggests because his offensive tackle matchups were, on average, tougher than the rushers getting the bigger offers.

The teams that sign the four-sack player I am describing will be criticized in April. They will be right by October.

The tape is the primary source. The contract is the outcome. Confuse them at your roster's peril.