Football Handicapping
For Experts Only
by Nathan Lake for ATSWins.com

If you talk to ten gamblers there is a good chance you will hear ten different ways to handicap football. Some suggestions might be valuable while others are useless. Most football handicapping techniques will fit into one of the four categories listed below.

• Power Ratings
  

• Trends and Angles
  

• Situational Analysis
  

• Match Up Analysis
  

Power ratings are used to assign a grade to every team and are statistics based. Subtracting the power ratings of two teams yields a mock pointspread which is compared to the sportsbook's line.

Trends and angles are tendencies that repeat; Teams that have won 2 or more games against the spread are 24-16-4(60%) as an away favorite since 2003.

Situational analysis measures the impact of outside influences. This may include the weather, injuries or a mid-season coaching change.

Match up analysis compares a team's style of play with their opponents. A position by position analysis might be used.

Basic Power Rating (PR)

Many handicappers use power ratings as the foundation of their sports handicapping program. The power rating is used to create unbiased pointspreads. Average margin of victory is the most common statistic used to create power ratings.

Basic PR = (Total Points Scored - Total Points Scored Against) /Games Played

Use the power ratings calculated for each team to predict the outcome of a game.

Pointspread = (Home Team PR - Away Team PR + 3) *-1

Subtract the Away Team PR from the Home Team PR, add 3.0 points for home field advantage and multiply the result by (-1) to show the Favorite as a negative number. A negative pointspread indicates a Home Favorite and a positive pointspread indicates a Home Underdog.

Using the AFC Championship game as an example:

1. Calculate team power ratings.

New England PR = (620 points scored - 294 points scored against) /17 games
New England PR = 19.2

San Diego PR = (457 points scored - 314 points scored against) /18 games
San Diego PR = 7.9

2. Calculate the predicted outcome or pointspread.

Pointspread = (New England PR - San Diego PR + 3) *-1
Pointspread = (19.2 - 7.9 + 3) *-1 = -14.3

We have calculated New England as a -14.5 point home favorite.

Advanced Power Rating

Unfortunately basic power ratings do not take into account a team's strength of schedule. A more accurate power rating can be calculated by averaging opponent PR's and averaging this number with the team PR.

Advanced PR = (Team PR + Opponent Average PR)/ 2

1. Calculate opponent basic power ratings.

2. Average opponent basic power ratings.

New England Opponent Average PR = -0.4
San Diego Opponent Average PR = 0.3

3. Calculate advanced team power ratings.

New England Advanced PR = (New England PR + Opponent Average PR)/ 2
New England Advanced PR = (19.2 + -0.4) /2 = 9.4

San Diego Advanced PR = (San Diego PR + Opponent Average PR)/ 2
San Diego Advanced PR = (7.9 + 0.3) /2 = 4.1

4. Calculate the predicted outcome or pointspread.

Pointspread = (New England Advanced PR - San Diego Advanced PR + 3) *-1
(9.4 - 4.1 + 3) *-1 = -8.3

After factoring in the opponents power ratings we have calculated New England as a -8.5 point home favorite.

Weighted Advanced Power Rating

A college football team's season can last more then four months and NFL teams will play up to five months if you include the playoffs. During this time a number of changes can take place and the team you saw play in September is not always the same team in December and January. To account for this change weighting a team's most recent performances may be necessary.

Accounting for bye weeks the above chart shows that New England and San Diego played nine games by the end of the tenth week. For simplicities sake let's give all games played after week ten twice as much weight.

1. Calculate team power ratings for the first ten weeks (9 games).

New England PR = (355 points scored - 147 points scored against) /9 games
New England PR = 23.1

San Diego PR = (212 points scored - 185 points scored against) /9 games
San Diego PR = 3.0

2. Calculate team power ratings for games played after week ten.

New England PR = (265 points scored - 147 points scored against) /8 games
New England PR = 14.8

San Diego PR = (245 points scored - 129 points scored against) /9 games
San Diego PR = 12.9

3. Calculate weighted team power ratings.

Weighted PR = (PR 1st ten weeks + PR after week ten + PR after week ten) /3
Make the denominator equal to the number of factors enclosed by parenthesis.

New England Weighted PR = (23.1 + 14.8 + 14.8) /3
New England Weighted PR = 17.6

San Diego Weighted PR = (3.0 + 12.9 +12.9) /3
San Diego Weighted PR = 9.6

4. Average opponent power ratings from the first ten weeks.