IDP rankings for Week 9

There really is nothing better than when a waiver-wire or free-agent acquisition becomes a star for your team. Andre Ellington saved my skin in at least two leagues this past Sunday, and even if I never play him again this season, I am forever indebted to him per the fantasy nerd honor code. One of my main hopes for this column each week is to help identify some defensive assets with the potential to positively influence a crucial midseason fantasy matchup the way Ellington did for so many owners this past weekend.

It's natural for ownership numbers to be a bit lower on the defensive side given the general lack of uniformity across IDP leagues, both in terms of roster size and scoring settings. Given this reality, I tend to view any defender owned in more than half of ESPN leagues to be a widely owned commodity. This often leads me to allocate more space and attention to players sitting below that 50 percent ownership threshold.

This doesn't limit how insane it is that Bills breakout rookie 'backer Kiko Alonso is owned in just 51 percent of ESPN leagues, but it does soften my stance on how often I might suggest proven producers might be somewhat underowned or underappreciated on the market. In some cases, like with Alonso, we can identify commodities that merit much more attention on the marketplace and simply demand discussion.

We're witnessing oddly low ownership for the Colts' Robert Mathis, a player with a very realistic shot at 20 sacks. Baltimore's Daryl Smith is another player trending toward a great fantasy campaign, but the market still isn't buying completely. If you identify some glaring gaps in performance and availability in your league, don't let ownership rates deflate your interest, as the "PTS," "AVG" and "LAST" tabs on our free-agent pages are far more important.

Front Four: The weekly word on the world of defenders

Tackle teams: We always want a little more of an edge -- extra insight into how we might be able to maximize our defensive rosters. One simple index I've been touting all season that remains an invaluable, and likely underused, resource, is our NFL stats page that houses opponent defensive statistics. Below is an example of one great category this stats page offers, ranking offenses by opponent tackle production. Surprisingly, the fast-snapping Eagles just miss the top 10 by a single tackle, as you can see the entire list here. Indicators like sacks allowed can be quite helpful, but we should also be aware of the offenses we might want to avoid facing when hunting sacks with our linemen or linebackers. Being aware of the most generous teams is very helpful, but it's also worth noting the offenses to avoid playing when possible or when seeking some informed influence for a tricky roster decision.

Opponent Tackle Production, This Season

Switching in Seattle: Bruce Irvin is finding success after shifting from defensive end to linebacker. The move confirms that he was indeed a suspect option as anything more than an undersized specialist on the edge. As a "tweener" prospect out of West Virginia, many pundits tabbed the Seahawks' first-round investment in Irvin a reach with high potential to fail as a full-time down lineman. Yet with the successful position shift so far, a return on investment for Seattle seems far more viable. On a defense rich in talent and personality, the second-year 'backer is now thriving (he enjoyed a career game in Week 8) and flying under the radar, as he's available in more than 80 percent of ESPN leagues. As a linebacker asset, Irvin isn't so compelling, given his penchant for meager tackle production, but with a knack for big plays and great usage on blitzes -- he's rushing the passer on nearly 33 percent of his snaps, the second-highest rate in the NFL among 4-3 outside linebackers with at least 180 snaps -- Irvin is a top addition given his dual eligibility as both a linebacker and a lineman in our game.

Sack race: The Colts' Robert Mathis has the potential to let investors down given that his tackle rate (just 4.4 tackles per game this season) is far below what we expect from a fantasy linebacker. Yet for the sheer upside of his sack production -- Mathis still leads the NFL in sacks even after the team's bye -- and the floor of his valuable role (he's rushing the passer on 94 percent of passing plays he's in for, the fourth-highest rate among 3-4 outside linebackers), Mathis needs to be owned and deployed in far more leagues; he's available in more than 80 percent of ESPN leagues. On pace for a record-setting 27 sacks, Mathis' favorable second-half schedule could see him challenge the all-time mark of 22.5.

Bargain bin -- Defenders available in more than half of ESPN leagues

Detroit's DeAndre Levy just missed the cut in the ranks, but that doesn't disqualify him from being an enduring value at the position given his uptick in tackles and breakout season in the interception department. ... The Vikings' Erin Henderson has 28 tackles over the past two weeks and yet is getting treated like a plate of vegetables out here. Add him and enjoy the consistent production. ... Mathis' teammate Jerrell Freeman is on pace for 91 solo tackles, nine sacks and five forced fumbles. He's owned in just more than 38 percent of ESPN leagues. ... Kyle Williams of the Bills is the rare defensive tackle worthy of weekly consideration, thanks to his awesome tackle production. ... The Pats' Rob Ninkovich has at least five tackles or sack production in all but one game this season. The Mike Vrabel clone continues to thrive as one of the last men standing on a decimated defense. ... Steelers stalwart Ryan Clark is coming off of a 12-tackle showing and should be busy policing the running and short-passing lanes versus New England this week.

Week 9: The Top 25 linebackers, linemen and defensive backs

So that we're working from agreed parameters, we'll use what many consider traditional scoring modifiers for an IDP league: Solo tackle (0.5), Assisted tackle (0.25), Sack (3), Interception (3), Forced fumble (3), Fumble recovery (3), Touchdown (6), Safety (4), Pass defended (0.5), Blocked kick (3).

Top 25 Linebackers

Top 25 Defensive Linemen

Top 25 Defensive Backs