We have new Patriots' tight end Alge Crumpler at No. 42 in our rankings. (AP)

Here’s part four of our training camp edition of “Rating the Roster,” looking at Nos. 50 through 41. (Nos. 51 through 60 can be found here, while No. 61 through 70, is here and No. 71 through No. 82 are here.)

As we previously explained, we settled on these rankings by considering a combination of factors, including overall ability, positional versatility, expectations, contract situation and place on the depth chart. We also looked at what might be best described as intangibles — loosely defined as a mixture of clubhouse character and willingness to work. In all, it helped us determine the overall value of each player within the Patriots system.

50. Defensive back Bret Lockett: Like Kyle Arrington, the 6-foot-1, 220-pound Lockett is a young and aggressive defensive back who was able to give the Patriots a lot of good reps on special teams last season, which should probably be enough to win him a spot on this year’s final 53. For what it’s worth, he also appears to be the Patriot who is most plugged into social networking. He has a very active Twitter account (where he revealed that he was working out on the West Coast with Tom Brady and Wes Welker), a web site and a Facebook page.

49. Offensive tackle Mark LeVoir: A massive tackle (6-foot-7, 310 pounds) who can provide depth — probably the No. 3 or No. 4 man at the position for the Patriots — he also lined up as an extra tight end on occasion last season. Someone who’s spent the last two seasons with New England, LeVoir isn’t the sort of guy you want as a starting lineman 16 games a year, but he’s certainly proven himself to be a worthy option when called upon in a pinch.

48. Offensive lineman Rich Ohrnberger: The Penn Stater — who has worked at guard and center — was active for only three games last season and saw time in one of them, but could get his chance for more time this season if Logan Mankins is missing for an extended stretch. A 6-foot-2, 300-pound interior lineman who the Patriots traded up to obtain in the 2009 draft, the thinking is that if New England goes with the versatile Dan Connolly at left guard while Mankins is out, Ohrnberger could move up the depth chart, stepping into the role that Connolly filled last season, at least on an occasional basis. But the organization remains very high on Ohrnberger, and it will be interesting to see if he will be able to develop given the fact that he should get more reps this summer and fall.

47. Defensive back Jonathan Wilhite: Like Terrence Wheatley, he had a strong rookie year in 2008 before dropping off. The difference is that Wilhite didn’t fall completely off the face of the earth like Wheatley did in 2009. After a serviceable rookie year, the 5-foot-10, 185-pound Wheatley was part of a busy secondary last season. However, he was pushed by Darius Butler last season, and it’s a safe bet that Butler should continue to eat into Wilhite’s playing time in 2010. Like many of the rest of his teammates in this section, Wilhite appears to be a solid situational player, but probably not a full-timer.

46. Running back BenJarvus Green-Ellis: When he’s gotten a chance to perform, he’s done very well — he rushed for 50-plus yards on three occasions in 2008, including a 105-yard performance against the Bills. But in this system, with all the veterans in front of him, he might not be anything more than an extra running back. The 5-foot-11, 215-pound Green-Ellis does have the benefit of having two full years in the system, which should give him an edge on Chris Taylor and Thomas Clayton for the final running back spot.

45. Defensive lineman Damione Lewis: A tough call. The 6-foot-2, 301-pound Lewis has always been a fairly reliable veteran, but there’s no way of knowing how he will fit in the New England defense. There’s room for him to move up or down as training camp continues. But for now, he remains something of an unknown quantity.

44. Defensive back/kick returner Matthew Slater: You can say a lot of things about Slater, but you can never question his attitude. (Having grown up in the culture of football — his father was Hall of Famer Jackie Slater — it’s probably not a coincidence.) The Patriots have tried the 6-foot, 200-pound Slater at several different spots (defensive back, wide receiver, returner) in an attempt to try and utilize his terrific speed. With the kick return game at a crossroads (Brandon Tate and Devin McCourty got some opportunities there in the spring) and the defensive back and wide receiver spots very crowded this summer, time could be running out on Slater.

43. Outside linebacker Rob Ninkovich: Ninkovich stepped in to provide some relief for Tully Banta-Cain on several occasions last year and performed as well as could be expected for a backup. Barring a surprise, the rock-solid 6-foot-2, 255-pound Ninkovich should be back in that role again this season, and will almost certainly work on special teams as well. His playing time could be tied to whether or not Shawn Crable is able to play — if not, Ninkovich’s reps will almost certainly increase.

42. Tight end Alge Crumpler: It’ll be fascinating to see how the 6-foot-2 Crumpler — who is apparently “down” to 275 pounds — works with the rookie tight ends. My guess is that he’ll serve as the primary blocking tight end, at least early on. Crumpler is also supposed to be a high character guy, and it will also be interesting to see how his leadership skills play out in the locker room.

41. Outside linebacker/special teamer Pierre Woods: That description for Woods should probably be flipped. A serviceable spot player at OLB who can still fill in there in a pinch, the 6-foot-5, 255-pounder out of Michigan really flourished on special teams the last few years — since 2006 he has more special teams tackles than anyone on the team. One of the best examples of the Foxboro philosophy: The more you can do, the more you can do for us.