Statistical Handicapping in the NFL: Part 2, Totals
October 17, 2006
Yards Passing (Total of 4 percentages):
I keep a five week moving average of the percentage of yards gained and allowed through the air for each team. All other things being equal, rushing favors Unders and passing favors Overs. The clock can never stop after a running play unless it goes out of bounds in the last two minutes of the first or last five minutes of the second halves respectively. If you have bet the Under, you want a shorter game with fewer plays. Conversely, when you bet the Over you want as many plays as possible; passing means the possibility of incompletions that will stop the clock. Lots of passing also increases the potential for big plays; either long completions or pass interference penalties. However, bear in mind the style of offense of each team. "West Coast" offenses can have a relatively high passing percentage, but some of those passes will be short ones that are in essence running plays. When the total of the four percentages is less than 250 I start to consider the Under. At greater than 270 I'm thinking Over.
Offensive and Defensive Efficiency (Vs NFL Average):
This again is a five week moving average. I track each team's yards per point on offense and defense and then compare it to the league mean, which is always about 15-16. It takes about 15 yards, on average, for each point scored by an offense or given up by a defense. Higher numbers mean an inefficient offense (or a defense that is harder to score upon). A low number means a defense that gives up points easily or an offense that scores them efficiently. All other things being equal, positive numbers favor Overs and negative ones Unders. I want both teams to be in the same category and tend to pass games where they are not. I look for ratings of 3 or more for each team with a total of greater than 6.
Offensive and Defensive Efficiency (NFL Rank):
This is ranking of the ratings used above. Offenses are ranked in descending order first to last, 1 to 32. Defenses are ranked in ascending order worst to best, 1 to 32. I look for a match of low numbers (i.e. a good O vs. a poor D) for Overs and a match of high numbers (i.e. a poor O vs. a good D) for Unders.
This is the same score from the "Sides" sheet.
Remember to look for value when using these stats. We are looking for games where the posted total is out of whack with the respective offensive and defensive statistics.
I make bets on totals when all the stats "fit" together either with an Over or an Under. If one stat is contradicting another (e.g. high percentages but negative yards per point) I pass.
Reed Hogben M.D.