In hopes of improving their pass rush, the Raiders signed defensive end Andre Carter, 33, to a free-agent contract on Wednesday. Though old by NFL standards, Carter should significantly improve the Raiders’ pass rush ability–or should I say their lack thereof?

The Raiders have three sacks in as many games, making their defensive line one of the worst in the league — third-worst pass rush in the league, according to Football Outsider (FO). The Raiders’ have an Adjusted Sack Rate (FO’s sack measurement: sacks plus intentional grounding penalties per pass attempt adjusted for down, distance, and opponent) of only 2.8%. ProFootball Focus (PFF) believes the Raiders actually have the worst, grading the Raiders pass rush as -18.3 — which is a measurement of the negative impact the line has on the game. PFF’s game tracking shows the Raiders to have only achieved 23 quarterback hurries this season, 22 fewer than the best d-line in the league (the Seahawks).

Okay, so all of those were just statistical ways of showing just how bad the Raiders’ pass rush is, something you’ve probably witnessed with your own eyes. Ultimately, Andre Carter’s signing really needs to no justification, but I’ll continue, if only to show why Carter will significantly improve the Raiders.

Football Outsiders’ statistics show Carter to be the second best Patriots’ lineman in 2011. His Stops (Stop), Defeats (Dfts), and Broken Tackle (BTkl) stats are outstanding.

Stops are the total number of plays in which Carter prevented, or stopped, the opposing offense from being successful. Defeats are the total number of plays in which Carter prevented a team from gaining a first-down on third or fourth down. And, Broken Tackles are the number of tackles offensive players broke while Carter was attempting a tackle. In all, Carter would have ranked second in Stops and first in Defeats were he a Raider in 2011. Nobody, other than Lamarr Houston, made more stops against the run than Carter in 2011.

ProFootball Focus’ stats essentially draw the same conclusion, except they provide a game-by-game breakdown.

Carter accumulated 51 total quarterback pressures last season–Kamerion Wimbley had 62. He also had 34 solo stops, which is better than any Raiders’ lineman.

In total, Carter is a plus defender when facing both the run and the pass. Currently, PFF believes that only Richard Seymour and Desmond Bryant have a positive impact on the game at their position. Which is to say, Carter’s addition is needed. If he is able to fully recover from a quadricep injury he suffered last season, he should instantly become the Raiders’ best defensive lineman.