2012 NFL Free Agents: Analyzing Mario Williams and the Best Defensive Signings

The NFL's 2012 free-agency period only began a few days ago, but my, has it been busy.

And to think, there are still some solid free agents available, as well as the NFL draft next month.

That being said, here's a look at the best defensive players who signed elsewhere this past week. In a offensive-oriented league, a beefed-up defense can give any team a distinct advantage.

Mario Williams, Bills

As reported by Adam Schefter of ESPN, the Buffalo Bills landed Mario Williams on Thursday in easily the biggest defensive free-agent signing this offseason.

Obviously, this is a great move for the Bills as their defenses allowed 371 total yards per game in 2011 (ranked No. 26). They also allowed an average of 27 points per game (ranked No. 30) and recording just 29 sacks.

Williams has the ability to fit whatever defensive scheme Buffalo chooses to run as well. He'll make for a stud 4-3 defensive end or a great 3-4 pass-rushing outside linebacker. The latter is the better fit, just because the Houston Texans ran a 3-4 as Buffalo did in 2011.

Perhaps the best thing about Williams' acquisition, though, is that this gives the Bills more options in the draft. With the No. 10 overall selection, Buffalo could still spruce up the front seven with a guy like South Carolina's Melvin Ingram or upgrade the secondary with Alabama corner Dre Kirkpatrick.

Another feasible option is to look at a receiver such as Notre Dame's Michael Floyd or take a top offensive lineman like Iowa's Riley Reiff. Since the Bills have Williams long-term, they could also trade down and stock up for 2013 and beyond.

Regardless, it's going to be interesting to see what Buffalo does in April.

Brandon Carr, Cowboys

In 2011, the Dallas Cowboys ranked No. 23 against the pass by allowing 244 pass yards per game. It was arguably the single biggest reason why Big D missed out on the postseason, which also comes as no surprise since Dallas allowed an average of 24 points per game in the final five weeks.

Finishing with a 1-4 record after beginning 7-4, the Cowboys were desperate to improve the pass defense. Well, as reported by Adam Schefter, signing cornerback Brandon Carr on Wednesday was the first step in the right direction.

Carr is a guy who's better than advertised at taking away half the field, plus he is a solid at edge run support. With 237 tackles (211 solo) and 65 passes defended (40 between 2010 and 2011) throughout his career, Dallas can focus elsewhere in the draft.

At No. 14 overall, the Cowboys can now look to depth at offensive line with Georgia's Cordy Glenn or Stanford's David DeCastro. Another option would be to take a defensive tackle like Memphis' Dontari Poe or Mississippi State's Fletcher Cox.

Both would fit well with DeMarcus Ware on the edge and Sean Lee at middle 'backer. Carr would obviously be responsible for locking down a good portion of the field and it coincides well with Big D's front seven.

Carr will allow Ware more time to get quarterback pressure and when Ware gets to the quarterback quickly, Carr won't have to be in coverage long. Defense is a two-way street and "The Doomsday Defense" is back on the rise.

Lofa Tatupu, Falcons

One of the more unnoticed free-agent signings, the Atlanta Falcons are giving linebacker Lofa Tatupu another chance. According to Orlando Ledbetter of the Atlanta Journal-Constitution, Tatupu is in for two years:

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The Falcons have agreed to terms on a two-year deal with linebacker Lofa Tatupu.

The move to sign Tatupu opens the door for Curtis Lofton to leave the team.

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At first glance, Tatupu to the Falcons may not appear as one of the better defensive signings and rightfully so: He missed all of 2011 and 11 games in 2009. He did, however, play the entire 2010 season; he recorded 88 tackles and defended eight passes (second most in career) that year.

Tatupu also collected 12 tackles that postseason and is a three-time Pro Bowl selection.

Despite his injuries in recent years, this is a big addition for Atlanta because the Falcons ranked No. 20 against the pass by allowing 236 pass yards per game.

For his career, Tatupu has 10 interceptions and defended a total of 39 passes. With new defensive coordinator Mike Nolan (who ran a 3-4 front in Denver and Miami), it's the perfect fit.

Have Lofa in the middle with Akeem Dent and then select a stud pass-rusher in Round 2 of the draft, and the Dirty Birds defense is set.

Cortland Finnegan, Rams

When you look at the St. Louis Rams and their 2-14 campaign last season, it's hard to believe they fielded a defense that ranked No. 7 against the pass.

However, that's the case as St. Louis allowed just 206.3 pass yards per game. Digging deeper into that ranking, though, and we see that the Rams had just 484 passes attempted against them; this was the fifth-fewest passes attempted against any team.

The Rams also allowed an 87.3 quarterback rating (ranked No. 23), behind defenses that gave up much more yards such as Green Bay, Oakland and New England.

In other words, for as little as it was challenged, St. Louis was not an effective pass defense given the number of opportunities. Then again, it didn't help that the Rams ranked No. 31 against the run, allowing over 150 rush yards per game.

This is why signing cornerback Cortland Finnegan, reported by Adam Schefter, was just what the Rams needed to do. It reunites Finnegan with Jeff Fisher and thanks to the Washington Redskins, St. Louis can add some top prospects in the NFL draft.

Finnegan's presence in the secondary will help with perimeter run support, locking down in zone coverage and simply bringing a physical attitude to the St. Louis defense. Against the NFC West—which isn't overly dominant in regards to passing offense—Finnegan is set up for a big 2012 season.

John Rozum on Twitter.