With half of the season completed, here is a defensive snapshot of player value through the lens of playing time stats (including penalties, small margin for error):
DEFENSIVE END
Chandler Jones (498 of 542) – 91.9 percent
Rob Ninkovich (436 of 542) – 80.4 percent
Jermaine Cunningham (260 of 542) – 48.0 percent
Trevor Scott (59 of 542) – 10.9 percent
Justin Francis (26 of 542) – 4.8 percent
Jake Bequette (17 of 542) – 3.1 percent
Quick hits: Jones is a leading candidate for defensive rookie of the year honors at this point, according to ESPN.com NFL scout Matt Williamson. … Ninkovich has played mostly end, but moved to linebacker for a short stretch when rookie Dont’a Hightower was out with a hamstring injury. … Nice rebound season from Cunningham, the 2010 second-round pick who has found his niche as an interior rusher in sub packages and backup end. … Scott, who came aboard as a free agent after four years in Oakland and was viewed as a potential Mark Anderson replacement as a nickel rusher, has been more of a special teamer. Part of that has been tied to Jones being so effective; the coaches don’t want to take him off the field … Francis (rookie free agent) is ahead of Bequette (3rd round) on the depth chart, in part because he has added special teams value (punt coverage).
DEFENSIVE TACKLE
Vince Wilfork (437 of 542) – 80.6 percent
Kyle Love (322 of 542) – 59.4 percent
Brandon Deaderick (87 of 542) – 16.1 percent
Ron Brace (60 of 542) – 11.1 percent
Terrell McClain (16 of 542) – 3.0 percent*
Marcus Forston (8 of 542) – 1.5 percent**
Quick hits: Wilfork is down a tick, from 86.8 percent last season, as the Patriots are finding spots to rest their captain and one of their best defenders. … Love is up a tick, from 50.5 percent last season. He’s staying on the field in some passing situations after being more of a pure two-down player in 2011. … Depth behind Wilfork and Love is thin, as Deaderick and Brace haven’t done much to stand out. … Myron Pryor remains on the physically unable to perform list and could help.
LINEBACKER
Jerod Mayo (528 of 542) – 97.4 percent
Brandon Spikes (419 of 542) – 77.3 percent
Dont'a Hightower (217 of 542) – 40.0 percent
Tracy White (14 of 542) – 2.6 percent
Niko Koutouvides (7 of 542) – 1.3 percent
Bobby Carpenter (6 of 542) – 1.1 percent
Jeff Tarpinian (6 of 542) – 1.1 percent
Quick hits: Mayo is the defensive signal-caller and is a three-down player who seldom comes off the field. The lone snaps he’s come off have been because of injury or at the end of games. … Spikes’ rise is particularly notable, as he’s strung together games without interruption from injury and/or suspension. He played 40.1 percent of the snaps last season, usually coming off in sub packages. But this year he’s staying on the field in the nickel, as evidenced by his higher total (77.3 percent). … Hightower missed almost three full games with a hamstring injury, lowering his playtime total. … Depth behind Mayo, Spikes and Hightower is thin. The trio has to be the NFL's biggest starting linebacker group.
CORNERBACK
Devin McCourty (530 of 542) – 97.8 percent
Kyle Arrington (436 of 542) – 80.4 percent
Sterling Moore (233 of 542) – 43 percent
Alfonzo Dennard (223 of 542) – 41.1 percent
Ras-I Dowling (84 of 542) – 15.5 percent
Marquice Cole (41 of 542) – 7.6 percent
Quick hits: McCourty has played safety the last two games and now that cornerback Aqib Talib has been acquired, keeping him there remains an option. The question is whether the Patriots see Arrington or Dennard as a strong enough option as a No. 2 corner alongside Talib in that scenario. … Arrington has hit a rough patch after winning the No. 2 job out of training camp. His playing time total would have likely been higher if he wasn't knocked out of the most recent game against the Rams after 6 snaps because of a concussion. … Moore, the team’s primary nickelback since Week 2, was available for any team to claim and no one did. That speaks to how his upside is viewed around the NFL. … Dennard has come on strong from a playing-time perspective after not logging a snap in each of the first four games of the season. …. Dowling is on injured reserve for the second season in a row, which is naturally a big disappointment. … 20 of Cole’s 41 snaps came last week against the Rams.
SAFETY
Tavon Wilson (369 of 542) – 68.1 percent
Patrick Chung (360 of 542) – 66.4 percent
Steve Gregory (229 or 542) – 42.3 percent
Nate Ebner (34 of 542) – 6.3 percent
Quick hits: A position that was a trouble spot in 2011 remains one this year, in part because of injury. … Wilson, the second-round pick out of Illinois who some analysts viewed as a reach at that point in the draft, was supposed to be a top backup. Instead, he’s been thrust into a top role because of injuries to Chung (shoulder) and Gregory (hip). ... That’s why the Patriots have tapped McCourty at this spot and might consider to do so. … Even when Chung has been on the field, the results have been uneven. … Gregory has been out since the fourth quarter of the Sept. 30 road against the Bills.
* No longer on team
** Currently on practice squad