Smartgambler Rugby Union

International Super 12 betting with Professor Ray Stefani

Smartgambler Super 12 Package

The Stefani system

An explanation from Professor Ray Stefani of how his system works in predicting Super 12 Rugby Union results, with some analysis from past seasons.

Super 12 Rugby Union Predictions

How It Works

I have adapted a system that I have been improving over the last 30 years, after more than 20,000 predictions in a variety of sports, to making predictions for Super 12 rugby.

I start with an offensive, defensive and total rating for each team from the previous season and then adjust that rating using season data. Each offensive rating is adjusted, based on

Points scored by the team
Opponent defensive rating
Home advantage

Each defensive rating is adjusted depending on

Points scored against the team
Opponent offensive rating
Home advantage

Total rating depends on offensive rating minus defensive rating.

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To predict score difference for the next game, I use

Weighted difference of total ratings
Home advantage

To predict the home team score I use

Score difference
Home team offensive rating
Away team defensive rating
Home advantage

To predict the away team score I use

Score difference
Away team offensive rating
Home team defensive rating
Home advantage

To predict total score I add the home team score to the away team score.

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I also predict the probability that each team will win, using

Score difference
Score error standard deviation
Normal distribution

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I show fair decimal odds for each game. Fair decimal odds are found by taking 1/probability. For example, if the probability of a home win is 0.5, the fair decimal odds are 1/0.5 or 2.0 (a bet of $1 will return $2, the original $1 and a profit of $1). If the odds of a win are 0.25, the fair decimal odds are 1.0/0.25 or 4.0.

The fair decimal odds can be used for money line betting. Score difference can be used for handicap betting. Total score can be used for over/under betting and actual score can be used for actual score betting.

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Challenges of Super 12

Currently thee are four teams from South Africa (Bulls, Cats, Sharks and Stormers), five teams from New Zealand (Blues, Chiefs, Crusaders, Highlanders and Hurricanes) and three teams from Australia (Brumbies, Reds and Waratahs). I use two separate home advantages, one for domestic competition and one for international competition.

Here is a summary of overall scoring and home advantage. The total score tends to be higher for international competition as does the home advantage (due to travel fatigue, as one of several factors).

Scoring and Home Advantage (Five Seasons, 1999-2003)

Accuracy of Picking the Winner

If you refer to my website you'll find that for 13,209 predictions in sports having few draws (ties) I picked the winner 70% of the time. I applied my prediction method to the 2001 to 2003 seasons of Super 12 and achieved a similar level of accuracy.

2001 - 2003 Super 12 seasons
Accuracy of Picking the Winner

Accuracy of Picking the Probability

Below you'll find probability data for picking the favorite for the 2001 to 2003 seasons of Super 12. Of course, if you want the non-favorite probabilities, just take one minus probabilities for the favorite. I show each probability range, the number of games, the predicted probability and the actual accuracy (how often the favorite won). There is close agreement. As more games are played, the predicted and actual figures should come even closer together.

2001-2003 Accuracy of Predicted Probabilities for the Favorite

Accuracy of Predicting the Score

Below are data for the 2001 to 2003 seasons relating to the picking the total score and actual score for the home and away teams. As you can see, the average errors are quite small. Each error equals the predicted score minus the actual score.

2001 to 2003 Accuracy of the Predicted Score

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