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Aug 22, 2016
Aug 22, 2016

## Apply Pythagorean theorem to NFL betting

A lot of groundwork for a successful NFL betting season is done in the often overlooked pre-season. One of the great Super Bowl betting tips is to use a spread betting strategy from the start of the season to give yourself the best chance of getting to the final game of the season in profit. Continue reading to find out more.

The memories of the Super Bowl might still be fresh, but the draft has now taken place and training camps are open, if you haven't done it already, it might be time to start thinking about an NFL spread betting strategy. This strategy doesn't try to predict who will in the Super Bowl, it aims to get you there in proft. As a bettor, how do you go about handicapping the first week’s games and trying to find an edge this far out?

As a starting point, you should look to understand the relationship between season wins and the first week point spreads. An average team would expect to win 50% of the time or 8 games in a 16 game NFL regular season schedule. In essence, the expected season wins for a team is just a power ranking.

How many games would you expect a team to win, if it was a 3-point favourite for each game? First you need to convert the no margin Money Line into a “percentage chance of winning” for each game. For favourites, that is the (Money Line / (Money Line odds – 100)) * 100. If the fair no-margin Money Line for a 3-point favourite is -145/+145, we would expect the 3-point favourite to win (145 /(-145-100)) * 100 = 59% of the time. If we knew a team would be a 3-point favourite for every game, we would expect it to win 16*0.59 games, or about 9.5 games.

### Converting season wins into a Week One line

Although not a perfect science, you can use this knowledge to convert season-win lines into a game line for the first week. For every ½ game better the favourite is for season wins, it should give up an additional 1 point on the spread at a neutral site.

If a 9.5-win team played an 8-win team, the 9.5 win team would be a 3-point favourite on a neutral field. After that, add 3 points for home field advantage, so the 9.5 win team would be a 6-point favourite at home, or a Pick’em on the road.

You then need to set a “baseline” using games from the prior year, in this case the 2015 NFL season. While some people will simply start with the number of games a team won in the previous season, more sophisticated bettors use the “Pythagorean Theorem” for football. This formula reduces the effects of lucky and/or close wins, and gives a team more credit for blowouts and consistently solid performances.

### Using Pythagorean Theorem

By way of example, consider the 2015 New England Patriots (current 2017 Super Bowl favourites at 5.610*)  regular season record of 12-4, with 465 points scored for and 315 points scored against. Instead of simply using their win/loss record, if you use the Pythagorean Theorem for football, you assume games won = (PF^2) / (PF^2+PA^2) * 16, where PF=points for and PA=points against.

Unlike other Super Bowl betting tips, the Season wins & Week 1 points spreads strategy doesn't try to predict a winner in the big game, it aims to get you there in profit.

Using the Pythagorean Theorem for football, the Patriots’ baseline would be calculated as 465*465/(465*465+315*315) * 16 which gives an expectation of 10.96 games. This suggests that New England was lucky to win 12 games and if they played the same season with the same roster, 11 wins would be more likely.

Conversely, when you use the Pythagorean Theorem for football, we can see that last year Dallas Cowboys’ record under evaluated the team. The Cowboys finished at 4-12, with 275 points for and 374 points scored against. Their baseline would be 275*275/(275*275+374*374) * 16 = 5.61 games, nearly 2 full games better than their record from last year.

The Pythagorean Theorem is a starting point in your spread betting strategy that gives you a leg up over handicappers who don’t use it. Compared to other Super Bowl betting tips, you might be playing the long game but it's certainly a much safer strategy. Although originally derived by Bill James for MLB, its applications have extended across many sports by changing the exponent (2 for NFL, 1.8 for MLB, and 16.5 for the NBA).

### Reversion to the mean

Another adjustment you can make to your season wins baseline is the "reversion to the mean”. Basically this means that no matter what a team does in a previous season, it tends to move towards winning 50% of its games the following season.

Bad teams aren’t quite as bad as people remember them and the dynasties eventually fade. A general rule of thumb is to move your baseline season wins about ½ a game towards 8 for baselines between 5.5-10.5, or a full game towards 8 for very good/bad teams outside that range.

Once you have your baseline, you should consider roster changes when developing your spead betting strategy. Is a team peaking or rebuilding? If you see lots of older players retiring and being replaced with younger, inexperienced players, this suggests a team could be in a rebuilding stage.

If many starters are inexperienced at the top level, you typically expect that team to fare worse the next year, but gradually improve afterwards.

Younger players tend to contribute less in their first few years and in a majority of cases, you can ignore the effects of the draft on a team and focus your energies on trades/free agents acquired. If many starters are inexperienced at the top level, you typically expect that team to fare worse the next year, but gradually improve afterwards.

If a team’s roster is fairly stable, you generally expect the team to do as well or better the following year. On teams with low turnover, what is the focus of the roster additions? Adding talented veterans to an area of a team lacking experience is the quickest way to impact a team.

Adding depth (e.g. a journeyman backup Q.B., or a fourth cornerback) will have less of an impact, but also lowers the downside variance. Analysing roster changes is a very subjective matter. For each one you decide to evaluate (and you might choose to ignore all changes involving third-string players or deeper), try to consider how that will affect the team’s play. If a team has a poor defense and an average offense, defensive changes will have a bigger impact – the defense simply has more room for improvement.

Once you’ve completed your season win expectations, set your line for each game. As in the example earlier, take the difference between the two teams in season wins, multiply by 2, and add 3 for the home field advantage. If your numbers suggest a play, the best NFL betting odds are available at Pinnacle.

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