It’s that time of year again. The NFL flea market is open for business, and this year, it’s open for a lot of business. Rather than list off the 50 or so players slated to hit the market, we decided to try to give a little insight into a few of the bigger names available this spring. As you yell at Twitter and friends about who your team needs, a little familiarity with the options can’t hurt.

Lamarr Houston, DE, Raiders

Age: 26

2013 stats: 56 tackles, 6 sacks, 2 forced fumbles

At the NFL combine last week, Colts head coach Chuck Pagano was asked a question about Erik Walden, the outside linebacker Indianapolis signed to a four-year, $16 million contract last offseason. The signing was initially met with some pretty harsh criticism. Walden had just three sacks as a 3-4 outside linebacker for the Packers in 2012. The lasting image anyone had of him that season was Colin Kaepernick running by, untouched, as Walden flailed his arms in the quarterback’s general vicinity.

In his first season in Indianapolis, Walden again had just three sacks and was generally abysmal as a pass-rusher while playing a pass-rushing position. Pagano, though, went a different route in assessing Walden. “Erik’s a good football player,” he said. “I think back to some of the guys we had in Baltimore, the edge-setters. When we went out and find outside linebackers, when we go looking for them in the draft or free agency, the first criteria is they have to be able to set the edge.”

Whether the idea applies to Walden (he is better as a run defender, but that’s by default) is a separate conversation, but it’s an interesting idea. Run defense for edge players is too quickly dismissed. For a lot of fans, it’s viewed the same way individual defense used to be viewed in the NBA — without any stats, it becomes inherently undervalued, but a standout is able to make life easier on the rest of the defense as a whole. And few do that as well as Lamarr Houston.

Taken in the second round of the 2010 draft, Houston’s sack totals in Oakland have never been overwhelming. The six he had last season were the most he’s had in his four years, and he’s currently sitting at 16.5 for his career. Houston is only 26, and he’s shown flashes as a pass-rusher (more on that in a second), but the play you see above is what’s going to get him paid. Against the Chiefs, Houston is lined up as a standup outside linebacker. It’s something the Raiders had him do a decent amount, but the general principles are the same as if he were playing defensive end. He attacks the outside shoulder of the left tackle, gets extension, and continues working his feet to maintain outside leverage. Jamaal Charles initially wants to bounce this play outside, but with Houston setting the edge, that’s just not happening. The run is forced back in, and waiting is a host of black jerseys.

Funneling the ball back inside would be more than enough, but Houston goes a step further and actually gets in on the tackle too. His tape is littered with plays like this — a product of his quickness, effort level, and how well he uses his hands.

Houston runs into problems when we talk about his pass rushing. His game is built more on leverage than explosion, and he isn’t going to beat many left tackles to the edge. That ability to use his hands and create leverage does create opportunities, though. This sack against the Broncos came while Houston was playing defensive end, but the way he got it — turning Chris Clark’s shoulders and moving inside — makes me think his value as a pass-rusher could come at a position where his tendency to choose power over speed could be an advantage. At 300 pounds and with his ability to hold up against the run, Houston could be a perfect candidate to slide inside to defensive tackle in nickel situations. It’s a trait that’s dramatically enhanced the value of the top two defensive ends who were slated to be free agents this year (Michael Bennett and Greg Hardy), and it would allow a team to maximize Houston’s ability on any given play. He’s already shown he can line up at defensive end and outside linebacker; playing a 3-technique for a team like Tampa Bay would solidify him as one of the more versatile linemen in the league.

Best fits: Tampa Bay, Oakland

Alterraun Verner, CB, Titans

Age: 25

2013 stats: 5 interceptions, 23 passes defensed

While part of Houston’s appeal is how many different defenses he might fit into, Alterraun Verner’s is that he has a particular skill — one that may not translate from scheme to scheme.

In Tennessee last year, Verner played a lot of “off” and “bail” coverage when the Titans were in man-to-man. At the snap, Verner gets separation from his receiver off the line of scrimmage, giving Stephen Hill some initial cushion. That cushion, and allowing receivers to get a free inside release, may seem like an easy way for teams to chew up yards on short throws, but what allows Verner to be effective playing this way is how well he anticipates and makes plays on the ball. He changes directions extremely well and also has a knack for diagnosing plays early. Those are traits that also allow him to be valuable in zone coverage, especially in the flat while playing Cover 2. He takes some gambles, but they’re typically calculated enough that he’s able to pick off balls that many corners wouldn’t even try for.

For the first half of last season, Verner was playing as well as any cornerback in the league, but he tailed off in his last several games. His worst performance of the year (and he wasn’t alone) came against the Broncos, when Peyton Manning and Eric Decker were able to exploit just about every shortcoming of Verner’s game.

On this fourth-quarter touchdown, Verner is again playing bail coverage, and he’s doing it on the left side of the defense (something he wasn’t asked to do often). Not long into his route, Decker makes a quick outside move to set Verner up for a move back toward the post. This is one of the problems with playing off a receiver. Decker is able to make a series of quick, subtle moves without interference, and Verner gets paralyzed as a result. With plenty of room to work, Decker is able to slide between the corner and safety for an easy score.

This is an instance of a very good quarterback and his receiver understanding how to take advantage of what’s typically a strength. But on what looked like Manning’s first touchdown to Decker earlier in the day, the Broncos are exploiting one of Verner’s actual faults. On the play above, which looks to be lit by Steven Soderbergh, Verner is playing press coverage with a single-high safety. Press coverage is not a strong point for Verner. At no point does he try to find the ball while it’s in the air, and although he’s in pretty good position, Decker is able to make a last-second play on the ball and pull it in on the 2-yard line.

Where Verner ends up and how he’s used will reprise the continuing conversation about how much scheme matters for cornerbacks. The debate about how Darrelle Revis was being used in Tampa Bay last year went on all season, and we all remember what happened when the Eagles decided to turn Free Agency Grand Prize Nnamdi Asomugha into a zone corner. Verner can be a great find for someone, but that would likely mean he’s allowed to play the way he’s comfortable.

Best fits: St. Louis, San Diego

T.J. Ward, S, Browns

Age: 27

2013 stats: 112 tackles, 2 interceptions, 7 passes defensed

This year’s safety class is headlined by two very different players. I wrote about Jairus Byrd as part of my All-22 All-Stars series before the 2013 season, with the argument for his inclusion being that he’s among the best center fielders in the NFL. That’s still true, and as everyone in the world starts trying to copy the Seahawks, grabbing the closest thing football has to Earl Thomas probably isn’t a bad choice. Both Byrd and Thomas are true free safeties — ground-covering, ball-hawking patrollers of the middle of the field who provide the rest of the secondary with a bit more leeway than they might have otherwise.

T.J. Ward is the second safety on just about everyone’s list, and if Byrd is the Earl Thomas in this ideal fictional secondary, Ward is Kam Chancellor. Like Chancellor, Ward spends a majority of his time as what amounts to an extra linebacker. He lines up in the box more often than not, and his best trait is his ability to help out against the run.

Sometimes that means knifing in for tackles like this one, but Ward is also able to take on blockers and hold up long enough to make plays as well. Later in the same game, he threw his shoulder into a fullback, tossed him aside, and again pulled Charles down just a yard past the line of scrimmage. For the season, no safety made as many impact stops in the run. Ward’s 66 run tackles (according to Football Outsiders) were tied for the most among defensive backs, and no one matched his 12 defeats against the run.

The same talents that make him an excellent run defender — physicality, solid tackling, and moving well downhill — also make him a valuable pass defender in certain areas. He’s not the destroyer of worlds that Chancellor is, but Ward has the ability to really limit yards after the catch, especially on throws in the flat. He’s limited in coverage, but for a team that needs a true strong safety, he’s about as good as they come.

Best fits: Eagles, Browns

Randy Starks, DT, Dolphins

Age: 30

2013 stats: 49 tackles, 4 sacks

Unlike the other three players here, Randy Starks isn’t a relatively young commodity coming off his rookie contract. He’s been around for a while, but as he hits 30, he’s actually playing the best football of his career.

Overall, the Dolphins’ run defense last year was one of the worst in the league, ranking 29th in run-defense DVOA. It’s a perfect example of how run defense is a function of all seven or eight players in the box, and not just the defensive front. Both Paul Soliai (also a free agent) and Starks were among the best run-defending defensive tackles in the league last year, but for as good as they were, Miami’s linebackers were just as bad. According to Football Outsiders, no linebacker in the NFL had a worse run stop rate than big-ticket free-agent acquisition Dannell Ellerbe.

Watching Starks on tape, it’s hard to believe the Dolphins could have been as bad against the run as they were. He does everything right, and he can do it all over the defensive line. Here, Starks is lined up as a 1-technique (between the guard and center) on the right side of the defensive line. As 1-techniques often are, he’s double-teamed at the snap, but he concedes no ground at all. Being able to absorb a double-team and maintain gap responsibility is all anyone could ask of him, but Starks goes a step further. As the guard moves off the initial combo block to the linebacker, Starks sheds the center and makes the tackle near the line of scrimmage. The entire play is Line Play 101, instructional-video stuff. You can’t do it better.

For a lot of players, having the size and strength to hold up as a 1-technique means they may not have the build to get by when asked to move to the guard’s outside shoulder. Starks isn’t one of those guys. This is from the same game, and here, he’s lined up as a 3-technique outside the right guard, Davin Joseph. Asking Joseph to reach Starks on this play is a tough assignment, and you can see why. Starks maintains outside leverage throughout the play, and again, he finishes it off by shedding Joseph and getting in on the tackle.

Starks isn’t a sudden pass-rusher like some of the other big-name defensive tackles, but the traits he shows off in the two plays above are why he can add something as an interior rusher. Starks is excellent at locking out his arms and creating separation from offensive linemen. In the run game, that means throwing them aside and spilling back toward the ball to make tackles. Rushing the passer, it allows him to see past his blocker to the quarterback. If and when the quarterback steps up, Starks is free to discard the man blocking him and make a play. It doesn’t make him as valuable as someone who’s going to instantly disrupt an opposing passing game, but it does allow him to chip in a little something extra.

Best fits: Falcons, Patriots