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Football’s “X” Factor – Measuring Teams’ Efficiency or Inefficiency

by Andy Iskoe of thelogicalapproach.com

Statistics are a necessity in determining and evaluating the strengths and weaknesses of teams in all sports and in making comparisons. Stats are the fundamental building blocks of handicapping and all other factors used in handicapping spring from some raw statistical data. In football the most common statistics used in evaluating teams are points and yards. Teams need to gain yards on offense to score points and on defense the objective is to prevent your opponent from scoring points by gaining yards.

It would seem reasonable that a team that gains the most yards would also score the most points, all things being equal. Likewise, the team gaining the fewest yards would be expected to score the fewest points. But, of course, all things are not equal. And there is rarely, if ever, a direct correlation between yards gained and points scored, or yards allowed and points allowed, for more than just a handful of teams.

Some teams, such as Minnesota’s 1998 offense, will rank first in both categories, or sixth, or last. Usually there are differences in a team’s yardage ranking and their scoring ranking.

These differences are generally accounted for by a team’s ability or inability to score within the opponents’ 20 yard line (the ‘red zone’), the performance of a team’s “special” teams in providing or preventing good field position, a tendency by the offense to turn the ball over or an ability on the part of a defense to force turnovers and the performance of a team’s defense to score on fumble and interception returns or to at least establish good field position for their offense.

A measure we’ve relied upon more and more in recent seasons to explain the reasons why a team’s yardage rankings differ from that same team’s scoring rankings is what we refer to as the “X” factor. It is very easy to calculate and by comparing two teams’ “X” factors we are able to draw some conclusions and understand why certain teams win despite having below average stats or why losing teams seem to move the ball well but fail to cash in.

To determine a team’s “X” factor, simply subtract a team’s scoring rank from its yardage rank. Separate ‘X’ factors may be determined for the offense and the defense and then combined to get an overall ‘X’ factor.

A neutral team, having an “X” factor of 0, will have the same yardage and points rank.

A team that ranks 15th in yards gained but ranks 9th in points scored (using averages) has an offensive “X” factor of +6, indicating they are scoring more points than their yardage ranking relative to the other 31 teams suggests. That team is either benefitting from cashing in when inside the red zone, is getting good field position and has less yardage to gain in order to score, or is getting points from defense and special teams’ play.

A team that ranks 17th in yardage but ranks 25th in average points scored has an offensive “X” factor of -8, indicative of a team that moves the ball but doesn’t score as much as they should.

Similarly, a team ranking 12th in yards allowed but 5th in points allowed has a defensive “X” factor of +7. This is a team that makes the big plays on defense despite allowing yardage, or faces teams that fail to get good field position or whose defenses and special teams don’t often score.

A team ranking 8th in yards allowed but 13th in points allowed has a defensive “X” factor of -5. This is a team that surrenders more points than expected based upon the yards they allow relative to the rest of the league, meaning that they often provide their opponents with good field position or allow big scoring plays, including allowing special team and defensive touchdowns.

The ‘X’ factor’s usefulness increases as the season unfolds since averages and rankings tend to stabilize after more than a handful of games are played. Early in the season – say after two or three games – there can be wide fluctuations in a team’s rankings and by extension their ‘X’ factor. If a team averages 300 yards per game for their first three games (a total of 900 yards) and then in game 4 totals 400 yards their season’s average increases from 300 ypg to 325 ypg and probably improves their ranking by several positions. If that same team averages 300 yards per game through seven games (2100 total yards) and then gains 400 yards in game 8 their seasonal average increases by only 12.5 ypg and their ranking position will be only a couple or three positions at best.

I generally like to wait for teams to have played four games before putting too much stock in the ‘X’ factor but that number is purely arbitrary. Conservative analysts might wait for six games to be played – still leaving nearly half the college schedule and ten NFL games to utilize this tool. More aggressive handicappers might need only a game or two or three before using the ‘X’ factor.

In looking to utilize the ‘X’ factor as a handicapping tool I like to look for matchups which feature a team with a positive ‘X’ factor when playing a team with a negative ‘X’ factor. I especially am attracted to such games where the favorite is the team with the negative ‘X’ factor. Even better if the favorite is negative on both offense and defense and the underdog is positive on both sides of the ball.

This type of ‘negative’ favorite has been playing inefficient football, being unable to correlate yardage gained or allowed with points scored or allowed. Conversely the ‘positive’ underdog has been getting contributions that often do not show up in the usual statistics. Or if they do they are often buried. The ‘X’ factor is a logical and easily understood measure useful in finding underdogs that are undervalued and favorites that are overvalued.

The analysis works well for both the colleges and the pros. Keep in mind, of course, with nearly 120 Division I-A college teams and just 32 pro teams there will be wider fluctuations in the collegiate ranks. In the pros a team with an ‘X’ factor of + 7 when facing a team with an ‘X’ factor of - 5 represents a significant spread. In theory (though never in reality) a team can rank # 1 in both yards gained and allowed but also ranks # 32 in points scored and allowed. Hence the maximum range for an NFL team is from + 62 to - 62. In the colleges that range is from nearly + 230 to - 230, quite a disparity.

In general I like to isolate ‘positives’ against ‘negatives’ in both the college and the pros and, as stated above, especially like these matchups when the ‘positive’ team is getting points. In the pros I like to look for a minimum positive/negative matchup of + 5 or greater vs. - 5 or greater. In the colleges I like to look for + 20 or greater vs. - 20 or greater.

Here’s a look at week four of the NFL in terms of each team’s ‘X’ factor, noting, of course that 28 teams have played just three games and four teams – who had Byes last week – have played only twice. For each game I offer a bit of a commentary related to the ‘X’ factor. For these purposes I am using a team’s overall ‘X’ factor rather than segregating them into offensive and defensive ‘X’ factors. The overall numbers, of course, are the same when adding the offensive and defensive ‘X’ factors together.

New York Giants (+6 ‘X’ Factor) at Green Bay Packers (-9 ‘X’ Factor) – Much of the Giants’ positive number comes from the seven turnovers they received from Washington, effectively rendering nearly meaningless much of the yards Washington gained since most of that yardage went for naught, resulting in turnovers. Green Bay’s negative ‘X’ Factor is due largely to their defense which ranks 21 in yards allowed but 30 in points allowed. Playing on the carpet in Indianapolis can do that. Note that a team’s ‘X’ factor is adversely impacted by allowing touchdowns rather than forcing the opponent to settle for field goals. Likewise settling for field goals rather than touchdowns on offense will have an adverse impact.

Philadelphia Eagles (+18) at Chicago Bears (+3) – Philadelphia has benefitted from a defense that has yielded yardage (ranking 24) but making defensive stops (ranking 7 in points allowed). This is obvious to anyone who watched the Birds beat the Vikings a couple of Monday nights ago. Chicago’s plus 3 comes from their defense being more efficient than their offense has been inefficient.

Washington Redskins (-17) at Cleveland Browns (+16) – This is the week’s greatest dichotomy and makes a case for taking the underdog Browns at home, even though they have been offensively challenged which is heightened by the loss of rookie TE Winslow. Most of Cleveland’s +16 comes from their defensive component while Washington is balanced in a bad way with a - 9 on offense and - 8 on defense.

New England Patriots (+1) at Buffalo Bills (0) – Keep in mind that both teams have only played two games so the chance for a deviation in yardage rankings vs points rankings is less than with teams that have played that extra game to date.

Oakland Raiders (-1) at Houston Texans (-15) – Oakland is pretty much neutral while Houston has been betrayed by allowing more points than their defensive yardage ranking of 15 would suggest. The Texans rank 27 in points allowed.

Indianapolis Colts (+6) at Jacksonville Jaguars (-9) – Both teams have been efficient but both have an extreme ranking. The Colts rank first in both yards gained and points scored but on defense they rank last (32) in yards allowed while their points allowed ranking improves slightly to 26. Jacksonville’s positive comes from a ranking of 8 in yards allowed that translates to a # 2 ranking in points allowed. They have the league’s least productive offense (32) but have managed to improve their points scored ranking slightly to 29.

Cincinnati Bengals (-8) at Pittsburgh (-4) – Cincinnati’s negative ranking comes from a drop of 4 on both offense and defense in points relative to yards. Pittsburgh is slightly positive on offense (+ 3) but more negative defensively (- 7) than are the Bengals.

Atlanta Falcons (+13) at Carolina Panthers (-8) – Surprisingly Atlanta is positive on both offense (+ 5) and defense (+ 8). Surprising because they have been rather inept on offense and not much notice has been given to their defensive improvement. Carolina – having played just twice - has most of it’s negative ‘X’ factor attributed to a defense that ranks 7 in yards allowed but the Panthers rank 19 in points surrendered.

New Orleans Saints (+10) at Arizona Cardinals (+18) – The Saints benefit from slightly better points ranking than yardage rankings on both offense and defense. Arizona’s huge positive stems from a defensive ranking of 26 in yards allowed but a 7 ranking in points allowed. Although Dennis Green’s offense has struggled the first year Cardinal coach has his team playing a bend but don’t break defense, witness the 448 yards they allowed to the Rams while St Louis managed just 17 points.

New York Jets (-10) at Miami Dolphins (-3) – In winning their first two games the Jets have been victimized by allowing an average number of yards (ranking 18) but a boatload of points (ranking 29). The Jets’ lone turnover of the season in the early moments of their opener against Cincinnati – which was cashed in by the Bengals – was enough to skew the relationship between yards allowed and points allowed by the Jets in just two games. As the season wears on the impact of that blunder will lessen – unless it is repeated. Miami is the classic example of an “Under” teams with their 31/32 correlation on offense with yards to points and their 5/7 correlation of yards to points on defense.

Denver Broncos (-8) at Tampa bay Buccaneers (-9) – Both teams have slight negative components on both offense and defense with the major discrepancy related to Tampa Bay’s # 10 ranking in yards allowed but # 17 ranking in points allowed.

Tennessee Titans (-2) at San Diego (+9) – Whereas Tennessee is essentially neutral San Diego has been able to capitalize early on, ranking 24 in total offense but 6 in points scored. But that offensive efficiency is half offset by their defensive inefficiency. The Chargers rank 19 in yards allowed but 28 in points allowed.

St Louis Rams (-4) at San Francisco 49ers (-22) – Some how Mike Martz vs. Dennis Erickson doesn’t quite come across as the expected chess match between Joe Gibbs and Bill Parcells. Particularly disturbing for the Rams is their offensive inefficiencies which have them ranked 8 in total offense but 18 in points scored. Some of that is compensated for by a defensive ‘X’ factor of + 6. San Francisco is an example of team that is very sloppy. Defensively they rank above average (13) in yards allowed but they are next to last (31) in points given up.

Kansas City (-5) at Baltimore (+12) – Surprisingly Kansas City is positive offensively with an 18/14 split. It’s a surprise because even though the Chiefs do not rank near the top in total offense as they did a year ago their points scored is pretty much where you might expect a similarly performing team to be with their + 4 offensive ‘X’ factor. Defensively their ‘X’ factor is only -8 since they can’t rank any lower than 32 in points allowed. They rank 23 in yards allowed.

Of the four ‘Bye’ teams this week the Detroit Lions have the best ‘X’ Factor (+ 22) which is due to sizeable contributions on both offense (+ 12) and defense (+ 9). Are the Lions a lucky team? A team that has been opportunistic? They have been outgained in each of their three games yet won two of them. Is Detroit just not a very good team and things will eventually catch up with them? Perhaps. But if after 7 or 8 weeks the Lions are still in the +15 to +25 range then we much credit the Lions with benefitting from those ‘other’ areas we cited at the top – those areas that just are not easily measured by looking at statistics in the usual or time honored way.

Dallas is the most negative of the Bye teams at - 18, largely due to an inefficient offense. Minnesota is at + 4 and Seattle is at + 11. The Seahawks are quite interesting because their offensive ‘X’ factor is a strong + 10 while their fairly neutral defensive ‘X’ factor of + 1 is simply to their defense being ranked second in yards allowed while allowing the fewest points in the league. Not much room for there to be much of a defensive contribution.

Part of successful handicapping comes from looking beyond the obvious numbers, beyond the wins and losses and pure points scored and allowed. Factoring the ‘X’ Factor into your handicapping regimen will point you in the direction of many undervalued teams and away from many that are overvalued.

Because it is so early in the season my reliance on the ‘X’ factor is far less than it will be in just two or three weeks. Yet the numbers in the games above will temper my enthusiasm for Green Bay (- 9 vs Giants’ + 6) and give me more of a reason to look at a game I had previously disregarded this week – Cleveland (+ 16) over Washington (- 17). Similarly the ‘X’ factors will not take me away from liking Buffalo over New England or Tampa Bay over the Broncos. In both games the ‘X’ factors are pretty close to one another. The ‘X’ factor does reinforce my preference for Oakland over Houston as well as Baltimore over Kansas City.

The following games have been specifically recommended to subscribers to my College & Pro Football Newsletter, information about which my be found by visiting my website.

BUFFALO + 6 over New England – The teams swapped a pair of 31-0 home blowout wins at opposite ends of last season. New England, of course, won at the end of last season en route to their Super Bowl triumph. The Patriots look every bit as strong this season after a 2-0 start while Buffalo played well but lost both games. Don’t be surprised if Buffalo does enough to keep this one close and an upset is very much possible as Super Bowl champs often have a stretch early the next season when they exhibit lackadaisical play. This is a Divisional rivalry and the foes are quite familiar with one another with several ex-Pats now playing in Buffalo. New England does have more weapons and should get the win but Buffalo has enough talent - and the motivation - to take this to the wire. New England wins but by just 16-13.

CAROLINA - 3.5 over Atlanta – Atlanta QB Vick continues to have more of an impact with his feet rather than his arm early in the season. The Falcons average just 132 pass yards/game and 177 rush yards/ game. Carolina is rested following a Bye. They are a better team on offense than they were in 2003 but the defense is still their strength. Atlanta has shown improvement on defense, especially against the run. This is the first Divisional game for each. Given Atlanta’s 3-0 start the Panthers will be well prepared and focused for this game -- that extra week of preparation is a big edge. Atlanta is facing by far the best defense they will have seen this season. . Vick will get his yards mostly between the twenties but inside the red zone expect the Carolina defense to shine. And look for Carolina’s underrated offense to have success. Carolina wins 24-16.

N Y Jets - 5.5 over MIAMI – The Jets are rested and playing with confidence while Miami is a team somewhat in turmoil. And now they have lost newly acquired RB Gordon for the season. The Jets have a long recent history of playing well against Miami even when Miami was the better team. But now the Jets are the team with the Playoff look and swagger. They need to avoid overconfidence here as they are facing a desperate 0-3 team. But as desperate as the Dolphins are they may not be able to shut down an efficiently functioning Jets offense. QB Pennington and RB Martin have had strong starts to their seasons. Miami’s woes are best illustrated by their ten lost turnovers by the offense and only three turnovers recovered by the defense. The Jets are more talented and clearly better coached and have more ways to win. New York Jets win 20-10.

TAMPA BAY + 3 over Denver – After a high scoring, fast paced opening win over Kansas City the Denver offense has sputtered, especially on the ground. The Broncos ran for 202 against a porous KC defense but could muster just 106 at J’ville and a paltry 37 at home vs San Diego. Maybe they miss RB Portis more than they admit. But Denver’s defense has been solid the past two weeks, limiting the Jags and Chargers to a combined 390 yards. They shouldn’t be severely tested by a Tampa offense that has shown little but this is a dangerous spot for the Broncos. It’s their second trip to the east coast in three weeks and that takes a toll. Tampa’s season may be on the line here and they are worth a look as a home dog. They have lost RB Garner to injury but do get RB Pittman back. And FB Alstott will have an impact. Tampa Bay wins 16-14.

Andy Iskoe has been a professional handicapper for more than 20 years and has been based in Las Vegas since 1991. He has fared well in many major handicapping competitions and contests including cashing multiple times in the prestigious Hilton Super Contest in which he finished third as recently as 2002.

For information on Andy Iskoe’s Newsletters and Premium Selections offerings please visit www.thelogicalapproach.com. He may be reached via email at logicalapproach@aol.com