Welcome to the first round of the NRL 2016 season!
I will be posting predicted outcomes (tips) for each game of the 2016 NRL season. These predictions will be posted each week before the beginning of each round, and (time permitting) I will be posting a “roundup” on the performance of the predictions. These predictions/tips are based on a machine learning algorithm which was “trained” using historic match results from 2009-2015. Details on the evaluation and performance of the algorithm on the 2009-2015 season matches can be found in ‘NRL Predictive Modelling-Deep dive’ which I would highly recommend reading if you plan to stake on any of the predictions.
Since this is the first tipping post, I will give you a basic rundown of the table:
The table shows the team predicted to win/lose, if the team predicted to win is at home or away, and the perceived probability of the team predicted to win (note that this will always be >0.5). The table also includes the bookmaker odds, edge and Kelly fraction. Since my staking strategy this year focus’ on head to head bets only (backing who I think will win) I have left off the probability of the losing team to win (which is simply 1-perceived probability). I have included the edge and Kelly fraction for those curious (and/or who want to use this as a staking guide).
The Kelly fraction below represents the fraction of the amount of the bank you would stake on the team to win (if using a Full Kelly staking strategy). The fraction is calculated using the perceived probability and bookmaker odds by using the Kelly criterion formulae. Recall the formulae is:
(Perceived probability of team winning*(Bookmaker odds -1) -(1- Perceived probability of team losing))/(Bookmaker odds – 1)
If we use the Brisbane Broncos vs Parramatta Eels match as an example the Kelly fraction is calculated by:
(0.573*(1.6-1)-(1-0.537))/(1.6-1) = -0.139
If you were using the Kelly staking strategy in this case, even though the model predicts Broncos will win (which is in agreement with the bookmaker’s prediction), because there is no edge over the bookmaker (edge and Kelly fraction is negative) you would not place a stake on the Broncos to win. Remember this holds only for those using the Kelly staking strategy, and if you read 2016 Staking strategy you might think twice about using this strategy in full. Even though I personally won’t be using a full Kelly strategy for this seasons staking I will simulate the outcome assuming somebody did use it (just for fun ;)) and present the results at season end.
Finally, some commentary on the predictions and historic results for the first round/s:
For 2016, round 01, the model agrees with the bookmaker favourites (that is predicts the same team to win as the bookmaker) in all games except the Gold Coast, Roosters and Tigers game/s where, in contrast to the bookmaker/s the model predicts these teams to win. The largest disparity is in the Tigers vs Warriors game where the model predicts a 60.07% chance the Tigers will win, whereas the bookies predict the tigers only have a 37.7% chance of winning.
NRL S2016 R01 Predictions
| Team to win | Home/Away | Team to lose | Perceived Probability | Implied Probability | Perceived Odds | Bookmaker Odds [1] | Edge | Kelly fraction | Tip |
|---|---|---|---|---|---|---|---|---|---|
| Brisbane Broncos | Away | Parramatta Eels | 0.573 | 0.625 | 1.74 | 1.6 | -0.052 | -0.139 | Brisbane Broncos to win against Parramatta Eels while Away |
| Manly Sea Eagles | Home | Canterbury Bulldogs | 0.591 | 0.588 | 1.69 | 1.7 | 0.003 | 0.007 | Manly Sea Eagles to win against Canterbury Bulldogs while Home |
| Canberra Raiders | Home | Penrith Panthers | 0.545 | 0.549 | 1.84 | 1.82 | -0.005 | -0.01 | Canberra Raiders to win against Penrith Panthers while Home |
| Wests Tigers | Home | New Zealand Warriors | 0.607 | 0.377 | 1.65 | 2.65 | 0.23 | 0.369 | Wests Tigers to win against New Zealand Warriors while Home |
| North Queensland Cowboys | Home | Cronulla Sharks | 0.681 | 0.741 | 1.47 | 1.35 | -0.06 | -0.23 | North Queensland Cowboys to win against Cronulla Sharks while Home |
| Sydney Roosters | Home | South Sydney Rabbitohs | 0.572 | 0.476 | 1.75 | 2.1 | 0.096 | 0.183 | Sydney Roosters to win against South Sydney Rabbitohs while Home |
| Gold Coast Titans | Home | Newcastle Knights | 0.577 | 0.5 | 1.73 | 2 | 0.077 | 0.154 | Gold Coast Titans to win against Newcastle Knights while Home |
| Melbourne Storm | Home | St George Illawarra Dragons | 0.701 | 0.725 | 1.43 | 1.38 | -0.023 | -0.086 | Melbourne Storm to win against St George Illawarra Dragons while Home |