An Introduction to IDP: Strategy and Guiding Principles

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By Greg Alan (4for4 Founder) on January 4, 2013

Greg Alan is the original founder of 4for4.com Fantasy Football and comes from a deeply statistical and analytical business background.

Critics of using Individual Defensive Players (IDPs) say it's too much work and not a good tradeoff. Perhaps. However, using IDPs can get you more of the things you enjoy most about playing fantasy football. Things like more strategy, more trading and of course more stats. 

Although IDPs can add to the fun, in most leagues, offense and scoring are still the main keys to winning in fantasy football. So, don't sacrifice offense for a few extra defensive players, unless your scoring rules strongly suggest so. All that said, having a roster packed with some exceptional IDP value could give you a nice edge. 
 
The strategy for drafting a good team of IDPs is a little different than it is for offensive players. So, how do you figure out which IDPs to draft? 
 
While there is no surefire system for predicting the top producing IDPs each season, there are a few trends and decent leading indicators. First, we'll dive into some IDP DOs and DON'Ts. 
 
 

IDP DOs 

 
DO expect to encounter scoring inconsistencies while browsing the stats.
Some defensive stats, particularly sacks and tackles, have been known to change from what was originally reported. Oftentimes, these discrepancies are not discovered until Monday or Tuesday or even later. And some times, changes are not discovered until game tapes are reviewed, which may not happen until well after the original results where reported. To alleviate this problem, your league should pick one source for it's official stats, and not change it during the season. If you use a quality stats service, the stats you receive on Sunday are generally pretty accurate and any changes should be well documented. 
 
 
DO study your rules for the finer IDP points.
Know exactly how many IDPs you start each week and at what positions. Some leagues use 1-DL, 1-LB and 1-DB, with eight offensive starters. Another popular scheme calls for 2-DL, 3-LB and 2-DBs. 
 
In any case, most leagues that use IDPs generally require you to start at least one DL, LB and DB. But, if you are free to start IDPs regardless of position - look to the LINEBACKER. The reason? Plain and simple, LB's often tally more points than DLs or DBs. 
 
The Overall Top IDP Rankings you find at 4for4.com considers a player's value given his position. This ranking method is designed to find the most valuable players across all IDP positions. That's why you see DBs, LBs and DLs on the list. 
 
But the fact is, LB's are often the highest scoring players, far and away! 
 
If you can start IDPs independent of position, find the best tackling LB's on the board and draft them at every turn - simply put, see the 4for4.com LB Cheat Sheet and draft from that!
 
 
If you play in a league that only use a small number (1-3) of defensive starters each week, then you may not want to draft them until very late. On the other hand, if the mix is closer to 50-50 (split between offensive and defensive players), don't wait too long or else the talent level will really drop off and you'll have a clear disadvantage on defense. 
 
 
DO understand your scoring system. 
Your league scoring system is very important. It is essential that you understand the finer points of your IDP scoring categories. For instance, how many points are scored for a sack versus a tackle? If sacks, interceptions and fumble recoveries are scored higher than usual (most leagues use 2-3 pts for each) then you may want to bump linemen and defensive backs up a little higher on your draft boards. Does your league award points for passes defended? This is a statistic that would place more value on cornerbacks and safeties. Does the length of a TD impact scoring? How do punt and kick returns figure in to the IDP scoring? If they do, the potential for a bonus TD increases dramatically and if distance scoring is involved, then that value jumps a little higher. 
 
A typical IDP scoring system looks something like this: 6 points for any TD (this includes offense, defense or special teams), 3 points for any turnover (fumble recovery or interception), 2 points for each tackle, 1 point for each assisted tackle, 3 points for each sack and 5 points for each safety. 
 
 
DO make sure you have a good linebacker. 
In many leagues, tackles are often the most important stats when it comes to fantasy football points. This point cannot be emphasized enough. If you only remember one thing from reading this article, make sure this is it - players that make more tackles are often the best IDP fantasy contributors. As a result, linebackers are to your defense as running backs are to your offense, the building blocks. 
 
The top IDP producers are always around the ball and will consistently provide you with excellent tackle numbers. Occasionally, they will add a sack or interception or maybe even a TD. However, tackles are their bread and butter. If you expect to have a strong unit of defensive players, try to grab 2-3 very productive linebackers. 
 
 
DO remember the kick returners. 
Similarly to WRs and RBs, some DBs perform double-duty as kick returners. Often, these are young, developing players with good playmaking skills. Usually they have also had a history of returning kicks in college. From an IDP standpoint, players that are regular kick returners are more valuable as they have greater possibilities to score TDs than non-returners. This could be the difference between an average IDP and a great one. The ideal combination would be a starting DB or nickel back, who also returns kicks. 
 
 
DO take a few chances on defensive rookies. 
Every season it seems that there are several defensive rookies that win jobs in training camp and start for their NFL teams right away. 
 
Some Historical Examples:
In 2003 we saw rookies like DB Terence Newman and LB Nick Barnett step up. During the 2004 season, rookie Jonathan Vilma made a big mark. The same can be said for Carolina's Chris Gamble. In his first two years in the NFL this DB made 13 INTs and 149 tackles. Also in 2005 rookie Shawne Merriman made some things happen, as he tallied 10 sacks and chipped in with almost 4 tackles per game. In 2006, rookie AJ Hawk showed what he could do. 
 
In 2008, rookie Jerod Mayo came up big with 128 tackles. James Laurinaitis registered 107 tackles and two sacks in 2009. Rookie Aldon Smith had 14.0 sacks in 2011.
 
 

IDP DON'Ts 

 
DON'T draft from the highlight reel, but rather from the stat sheet. 
Oftentimes, the best fantasy IDP players are the quiet team leaders that just go about their business each week. Guys that make the flashiest plays and end up on the ESPN, CBS or Fox highlight reels aren't always IDP studs. 
 
Do you remember back in 2002, the Baltimore-Denver Monday Night Game? DB Chris McAlister of Baltimore scored an NFL record, 107-yard TD on a field goal return. Thinking they uncovered a gem, plenty of people claimed McAllister the following week. But, that 107-yard play was almost his entire fantasy contribution that week. Aside from the TD, his only made 2 tackles that night. On the other hand, DB Gary Baxter had 11 tackles. In almost every scoring method used, Baxter's game was much more valuable than McAllister's, yet most focused on McAlister, not Baxter. Think stats, not highlight reel material. 
 
The take is clear -- study the stats. A little homework could go a long way. 
 
 
DON'T overvalue forecasted turnovers and TDs. 
Both of these stats fall into the "pure bonus" category. While it's certainly nice to have a player that is consistently able to produce TDs and turnovers, the fact is, there are very few who actually do. For instance, it's very hard to predict interceptions from year to year -- especially if you try and do this over hundreds of NFL players. Be careful about projected defensive stats, they may look good in a spreadsheet - it all looks very precise. But, the problem is you could end up being "precisely wrong." 
 
A typical example is old NFL veteran LB Donnie Edwards. He had five picks in 2002, after having none (zero) in 2001. In 1998 Edwards had zero, only to follow that up with five in 1999. 
 
The message is clear, predicting LB INTs is risky. Don't let anyone kid you.  
 
DBs have an increased opportunity to make interceptions. However, even that is somewhat misleading. As an example, Tampa Bay's Ronde Barber had 10 INTs in 2001 and had a cumulative total of eight in his prior four NFL seasons. In 2002 and 2003, Ronde pulled in two INTs each year. In 2005 Barber had his 2nd best INT year - with five picks (half of what he had in 2001). In 2007 only two, but in 2008 he came back with four INTs. 
 
As for IDP touchdowns, they are rare. So don't put much weight in them from year-to-year. Example: One year, All-Pro linebacker Derrick Brooks had three TDs. But, over his 15-year NFL career, he's "only" averaged 0.026 TDs per game.  Further, in 2008, only four LBs even scored a defensive TD. 
 
 
DON'T plan for defensive injuries. 
Oftentimes it's good to plan for a potential injury to your top RB or QB. For defensive players this is not necessary and could result in wasting a roster spot on an extra IDP. Due to the fact that there a simply a greater number of defensive players to choose from, the talent pool will be a little more flooded for IDPs than it is for their offensive counterparts. The second stringers are often already starting at other positions (i.e. an outside linebacker that backs up the middle guy), or are obscure players whose main playing time is on special teams or situational duty. In other words, the large free agent player pool will generally have an adequate stopgap player when the need arises. 
 
 
DON'T be a leader or a follower; choose your team for value. 
The smart fantasy owner knows that the best value for an IDP is not likely to be early in the draft. The fact is that there are sure to be plenty of players with near equal fantasy effectiveness available in later rounds. You may not get the superstars, but value is easily found. There will always be at least one owner that grabs a defensive player way too early -- for example in the top 5 rounds in a 30-round draft. Don't be that guy and sacrifice a potentially higher valued offensive player for the high profile defensive player. You may find out later that better value could have been obtained by having two pretty good IDPs plus the 2nd wideout you grabbed with your pick instead of that one sexy IDP. 
 
Generally speaking, fill your key starting offensive positions (QB, RB, WR) and maybe take a backup or two before worrying about IDPs. 
 
Also, try and avoid following the pack. If someone else starts a run on defensive players, turn your attention elsewhere and find that sleeper running back, while other owners are busily checking their lists to be sure they don't miss out on the IDP run. 
 
In general, when drafting offensive players, you want to be the manager that starts the run at a position, not the one that's ending it. However, as an IDP guidepost, remember this -- don't be the first to pick an IDP in your draft, nor the last. 
 
So when is the best time to select an LB? The real answer to that question is: when it is best for your team. If you find yourself eight or 10 rounds into the draft and still don't have a WR, it probably wouldn't be your best value to choose a DB, even if he is the best one on your board. On the other hand, if you have chosen your team with good balanced picks, (i.e. 1 QB, 3 RB, 2 WR) then a top-tier linebacker could be a good value pick for you in the 7th or 8th round. 
 
 
Next, we take a deeper look at each position. There are a few things that make each defensive position unique. 
 
 

DEFENSIVE LINEMEN 

Other than tackles, sacks and a few assists, these big guys usually don't score much. A few may contribute an interception or fumble recovery every so often, and maybe even take it "to the house." However, these are rare occasions. 
 
Here are a few things to look when selecting your defensive line players. 
 
1. Sacks are golden, but you still need tackles. When choosing defensive linemen, the ideal player is a good run stopper and is also just as good at rushing the QB. The best players are able to contribute points in many scoring categories. Most DLs are not going to give you tremendous tackle totals, anything more than 40, or approximately 2.5 per game, would be considered excellent. When people think of defensive linemen, they usually think sacks first. As a result, the guys that get to the QB more often will get drafted first. But don't worry, by knowing the run stoppers, the guys that get tackles along the front line, you can still find value after the sack leaders are long gone. 
 
2. Beware of 3-4 defenses. The main responsibility for a lineman in 3-4 sets is to create a mess and take up space, thus freeing up the faster, more athletic linebackers to make the plays. They generally go unnoticed and have less opportunity to make sack or tackle. More often than not, the down linemen in 3-4 schemes are not as productive as those in 4-3 sets. Choose players from these teams carefully. 
 
3. Versatility is a key. It makes sense to say that the players who are on the field more often, get more playmaking opportunities. Therefore, players that move around in certain situations may be a bit more valuable than those that get rotated in and out and don't play on every down. 
 
4. Look for players on good teams that have easy schedules. This is more of a theory than a statistical certainty. However, if it is combined with strong, secondary coverage, it makes for a good indicator of success. Think about it, this combination often results in the good team running up big leads, generally forcing opponents into obvious passing situations. With good coverage in the secondary, the QB will take more time to throw the ball, allowing the rushers to get there and make more sacks. 
 
 

LINEBACKERS 

To win, you often need several, better-than-average linebackers. An LB's ability to score fantasy points via tackles often allows them to outscore lineman and defensive backs. 
 
When in doubt about an IDP decision, always go for those that make more tackles. 
 
Other things to consider: 
 
1. Team's Heart and Soul - Former 49ers Head Coach and Chicago Bears Hall of Famer Mike Singletary has often been called the prototypical middle linebacker. His aggressive, fiery style of play has become the standard that others strive to achieve, and spawned the term "Mike" linebacker to refer to the man in the middle. In many cases, this is the leader of the defense, the guy that opposing offensive schemes are often designed around. In general, starting middle linebackers are well positioned to be effective fantasy players. Being in the middle of most every play obviously helps them ring up stats. Therefore, any player starting as a MLB is worth watching. 
 
2. Outside speed never hurts. Not everybody can be a middle linebacker. Sometimes the faster, speed guys are more effective on the outside, like Packers LB Clay Matthews. Pay attention to the terms "strong side" and "weak side" linebacker. Players that line up on the same side as the offensive tight end are considered "strong side". Those that line up opposite the tight end are "weak side." Oftentimes, the tight end is the extra blocker on running plays and ties up his coverage - the strong-side linebackers, leaving others to make the tackles. This could have a negative impact on the strongsider's fantasy value. On the other hand, the weakside backer is left more unencumbered to make the plays and thus has a little more value. Those that possess great speed and play on blitzing defenses could have tremendous upside. As for the strong side players, speed also helps tremendously. It allows them to shed blockers more quickly and get to the corner on the pass rush or perhaps drop into coverage when needed. 
 
3. Find players with a good fit. Sometimes, a player is signed as a free agent or acquired via trade or even promoted from a lesser role, to a new role that is a perfect fit for his talents... like lining up linebackers as defensive ends and vice versa, to disguise a 3-4 and 4-3 fronts. 
 
4. Look for players on bad teams. Teams who are on the losing side of the scoreboard, generally produce players with more tackles. The reason for this is because of their opponents' tendency to control the game by running the ball. If the interior defensive line is also weak against the run, the likelihood for increased middle linebacker production is even greater. 
 
 

DEFENSIVE BACKS 

Each time the ball is put in the air, it is likely that a defensive back is going to have a chance to make the play. However, before you can determine the real value of defensive backs, you must double-check your league scoring. If you play in a league that uses "passes defended" as a scoring category, it makes for a slightly different picture than leagues without them. When included, they generally increase the value of defensive backs quite a bit. Still, any way you do it, your goal is to find DBs who are always around the ball. 
 
1. The tacklers ensure consistency. A common myth is that the best fantasy defensive backs are those that get the most interceptions. While that is certainly a key statistic, once again it is the tackle that tops the list as the simplest way to determine a players' fantasy value. Defensive backs are in the position to make more interceptions, however to be able to predict that and determine fantasy success is a tough call (again we want to be 100% transparent here). 
 
While several of the top scoring fantasy DBs do have interceptions and that factors into their season stats, those that consistently contribute tackles are more successful. 
 
 
2. Play it safe, pick a safety. The job of the cornerback is well defined - keep close to the wide receiver and don't give up the reception or big play. Meanwhile, it is the safeties that are free to roam around and make adjustments based on the prevailing down and distance. Sometimes they will provide double coverage, sometimes they will crowd the line looking for the run and sometimes they just end up being in the right place at the right time. Furthermore, on teams with weaker front line and linebacker corps, the safeties are more often forced to make the play. What does all this mean? In most cases the safety will be in a better position to make more plays by acting like a second middle linebacker than a cornerback will. The NFL veterans that have been around for a while have a better knack of knowing where to be.  
 
3. The scoop on the cornerbacks. In general, the following is true regarding cornerbacks and their fantasy effectiveness: the better they are by NFL standards, the worse their fantasy production is. 
 
To prove the point, check out this historical breakdown --- several years ago, the AFC/NFC Pro Bowl cornerbacks were Champ Bailey (58), Troy Vincent (73), Bobby Taylor (67), Ty Law (35), Aaron Glenn (39) and Patrick Surtain (80). Collectively, their highest fantasy ranking, based on point totals, which are shown in parentheses, was #35 by Law. The reason for the apparent "lack of production" from these players is simple -- they represented the league's best cover cornerbacks. They were so good at their jobs back then, that teams avoid throwing the ball in their direction, which leaves them fewer opportunities for tackles and interceptions. 
 
By contrast, rookie and inexperienced corners can sometimes produce excellent fantasy numbers simply because those same cover skills are targeted. 
 
4. Use the schedule to your advantage. Look for matchup advantages that you can parlay into success. For instance, when good teams with high-powered offenses play bad teams, the result is often predictable. The bad team will be playing catch up and will likely throw the ball more often. This could lead to higher tackle and big-play opportunities for the DBs. Another thing to look for is matchups against top WRs. Regardless of the player covering him, the league's top WRs often get their share of balls thrown their way. This could temporarily inflate a corner's' numbers. Also, there are several offenses that will simply throw the ball more often than others, no matter who they are playing. 
 
5. He could go all the way! Defensive TDs are somewhat more predictable for defensive backs than linebackers or linemen. Watch as the season progresses for those teams who seem to make the big plays. It seems like each year, there is at least one defensive team that scores a bunch of TDs once they get on a roll. 
 
 

Situational Play Calling in the NFL 

If a team is ahead, especially late in the game, they'll try to run the ball and kill the clock. On the flip side, teams on the losing end of the score have a greater tendency to throw the ball. We all kind of know this, but below quantifies the phenomenon and offers data-driven proof. 
 
The following 4for4.com exclusive table is based on over 1,000 NFL games. 
 
NFL Team Tendencies - Rushing the Ball by Situation
 
  by 1-6 by-1-6 by 7+ by 7+
Situation 1st Half 2nd Half 1st Half 2nd Half
Team Ahead 46% 52% 46% 61%
Team Behind 45% 37% 41% 25%
Example: The table above shows that if a team is winning by 7+ points in the 2nd half, that team will run 61% of the time. 
 
 
A few ways to leverage the above chart:
 
1) If a team is trailing, they'll be facing plenty of rushing attempts. And, in turn that gives the IDPs on the losing team a clear opportunity to pile up tackles and pad their IDP stats. Keep this in mind during the season and you'll also be able to pad your FF points each week. 
 
2) LBs are king when it comes to IDP and tackles are the stat that drives the LBs value. During the season, try to get a top-tier LB matched up against a top-tier running team. The result is often big-time stats for your stud LB. 
 
3) When trailing, poor running teams are often forced to pass 75% or more of the time in the second half. For the astute IDP player, that's great news. In these situations you want to seek out the opposing DBs. Because the poor team is passing so often, your DBs will be making plenty of tackles. 
 

Some Final Observations 

Week to week, while selecting defensive players, find players going up against the BEST offenses. In fantasyland, it's all about tackles. And, that's the most predictable stat for defensive players. Trying to predict an interception is much harder, especially at the individual player level. As for sacks, that's predictable to a degree, but generally only for defensive linemen. LBs and DBs typically get sacks on a blitz or on a broken play - and neither of those is easy to forecast on a weekly basis. 
 
Forecasting DLs each week can be tricky. However, there will be obvious matchups where your defensive lineman will be facing either a weak offensive line or a slow/young/indecisive quarterback who tends to get sacked a lot. In these cases, you need to take that into consideration. 
 
Linebackers are the most consistent IDP options. Generally, it doesn't matter if they are playing a running team or a passing team, as both plays often end up being covered by a LB anyway. What you look for here is how good your player's opposing offense is. If it's a top-flight opposing offense, it's an easy pick. Top offensive teams will most likely be on the field the majority of the time and the opposition will get a major workout. It's also important to consider how BAD your IDP player's teammates are. After all, if his teammate can't make the tackle, that gives your man more opportunity and more time on the field. 
 
If your league doesn't differentiate between outside linebackers and middle linebackers, you'll want to start as many MLBs as possible. Given that, your starting LBs shouldn't change much if you've collected some of the finer run stopping MLBs from around the league. 
 
With defensive backs everything is REALLY backwards. For instance the best fantasy CB is often considered a below average NFL cornerman. The better the talent, the more established the player, the less they'll score. Opposing teams often game plan to avoid throwing at these good NFL cover guys. Another huge factor in CB production depends on a player's opposite CB. But, two good CBs (on the same NFL team) have a chance at actually scoring because teams have no choice but to pass against them. What rises from this is the true value at CB: young and inexperienced guys getting their big chance. In other words, the rookie and 1st year starting corners will generally be IDP bargains, if they get the playing time. Also, the guys playing across from the best corners are always consistent tacklers because opposing teams are constantly throwing their way. If your league doesn't differentiate between corners and safeties, search out the best run stuffing safeties you can find. 
Filed Under: Preseason, 2010