Favorites covering in the NFL once again

Simon Noble of PinnacleSports.com discusses the recent trend of favorites covering in the NFL and gives players a tactic to evaluate teams based on their offensive and defensive yards per play.

 

Until recently, sharp players routinely turned a profit using very little handicapping and simply playing underdogs. Blindly betting every home dog of +7.5 or more during NFL season became a staple that regularly cashed at the window. Then this traditional handicapping technique stopped working to the point that these “bread and butter” plays no longer brought home the bacon. In 2005, the “Sharps 101 playbook” was rewritten as favorites covered 58% of the time.

Although it’s only the fourth week of the season, at Pinnacle Sportsbook we’ve noticed that this trend may reestablish itself as good teams dominate. Teams that are 2-1 or 3-0 are a combined 32-12 (72.73%) against the spread. With underdogs of 10 or more points only covering 1/3 of games this season it certainly brings league parity into question.

There’s always been a gap between the “haves” and “have nots” in the NFL. Prior to the 2002 season, this gap was bridged by scheduling four games for each team based on the previous year’s performance. If a team finished last in its division, the “crème puff” factor dictated that it would get four games against equally bad teams.

Since 2002, new NFL scheduling rules dictate that only two games per year would be based on a team’s record from the preceding year. As a result, today’s NFL schedule now contains more games between mismatched teams than before. Consequently, bad teams lose more games while good teams win more often.

This was extremely evident last year when only 1 of 32 teams finished with an 8-8 record. With the ever-growing number of underdog players and more mismatches, there are now profitable opportunities to do what was previously unthinkable - back quality teams as large favorites. Since there are several underdog players at Pinnacle Sportsbetting, which also offers up to 60% better odds on NFL sides, there’s often great value to be found betting favorites.

One way to evaluate a team is to look at its offensive yards per play and the defensive yards allowed per play. As one would expect, teams that gain more yards than they allow tend to win. While this isn’t exclusively accurate, this measure is at least as good a predictor of future performance as past game scores. Using the Internet and Excel, you can easily evaluate the entire league in just a few minutes. Scraping data and analyzing it in Excel is a mandatory skill for successful handicappers, so it’s worthwhile to provide a brief example of how simple it is.

Under the “Stats” section on NFL.com simply select “2005 regular season”. At the bottom of the page under “Sortable team rankings”, there are “Offense” and “Defense” options. Simply clicking the “Find stats” button after selecting total offense or defense, will give a number of statistics for every NFL team including offensive/defensive yards per play (Y/P).

Copy the offensive and defensive yards per play into an Excel spreadsheet sorted for each team’s individual stats. Then simply subtract the defensive yards per play from the offensive yards per play. If the “A” column is the team, and “B and C” are offensive and defensive yardages respectively, use the formula “=b1-c1” in column D. This will give a “yardage differential” for each team, which if positive, indicates a team that gains more yardage on offense than it surrenders. If done correctly, the spreadsheet should look like this:



 

The four worst teams in terms of yardage per play differential in 2005 were San Francisco, Houston, Buffalo and Detroit, while the four best were the New York Giants, Indianapolis, Pittsburgh and Seattle. Betting lines often fail to adequately reflect the difference between the elite teams compared to the dregs. The top four were 6-2-1 against the spread and 9-0 straight up in 2005 against the bottom four.

While these results aren’t surprising, a yardage differential can also be used to analyze match-ups between nearly any two teams. There’s a “quick and dirty” rule for setting a spread using NFL yardage differential: each 0.15 yards per play is worth 1 point. As an example, let’s examine Monday’s game of Green Bay at Philadelphia.

According to NFL.com, the Eagles are gaining 6.7 yards per play this season, while allowing 5.0 yards per play – a differential of +1.7. The Packers are gaining 5.4 Y/P, while allowing 5.9 Y/P, for a net differential of -0.5. The Eagles’ net differential is 2.2 better; dividing by 0.15 suggests the Eagles should be about a 14.5 point favorite on a neutral field.

As with all tools for evaluating teams, this calculation is best used in conjunction with other handicapping methods and using common sense. Many statistical methods become far more viable after 4-6 games so the current season’s data can be analyzed. However, even at this early stage, these types of statistical methods can be a good way to look for new winning angles – like identifying under-priced big favorites.

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Simon Noble, www.pinnaclesports.com

Originally published September 27, 2006 8:55 pm ET