2011 Round 13 Results: Unlucky? Probably Not

Carlton protected Investors from the horror round by recovering from a slow start against the Swans to eventually win by almost 6 goals, but the Saints and the Dons precluded Portfolio profitability this week by going down by 21 and 28 points respectively. As a result, Investor Portfolios dropped by about 1.5c across the round.

(As it turned out, enforcing the Line Fund prohibition on Away team wagering was a good thing this week, as line betting wins by Richmond and Geelong would not have been enough to offset the loss incurred from a large wager on Sydney. So that's one thing for Investors to be grateful for.)

Seven favourites won this week - the Dons being the only exception - which meant another solid week for head-to-head tipping. The all-tipster average was 6.1 from 8, the 2nd-highest average this season, trailing only last week's average of 7 from 8. The week's best performances were seven from eight, which came from BKB, Ride Your Luck, Follow The Streak, Bookie_3, Bookie_9 and the three Combo tipsters.

Bookie_9 and Combo_NN_1 continue to lead the Head-to-Head tipster table, each now on 74.5 from 101 or almost 74%. BKB is third, one tip adrift, and then come Bookie_3, Combo_7 and Combo_NN_2 on 72.5. Home Sweet Home remains last on 58.5 from 101 (58%), having scored just 5 this week to complete a 21 from 40 performance over the last 5 rounds.

A 58% win rate by home teams is about what we'd expect based on home team records for the period 2000 to 2010, as the following table attests.

The only home teams to have won at a rate below historical averages are those with Excess Venue Experience of 10 or more - that is, those home teams that have played at their home venue on 10 or more additional occasions than their opponents. This season these games have mostly been home games for Adelaide, Brisbane, Fremantle or West Coast, which amongst them represent 20 of the 35 clashes where the Excess Venue Experience has been this high.

MAFL Margin Predictors also recorded better-than-average results for the round, collectively producing an MAPE of 26.64 points per game, the 4th best this season. Best amongst them was, yet again, Bookie_3, this week registering an MAPE of 23.06 points per game to now lead Combo_7 by almost 1.2 points per game across the season. The week's worst round belonged to Win_7, which still managed a creditable sub-30 performance of 29.14 points per game.

Average line betting performance was once more at odds with the relative ease of head-to-head tipping and margin prediction, the mean line betting performance of 3.2 from 8 ranking the current round as only the 10th highest of the 13 to date. Combo_NN_1 produced the best round at just 5 from 8. Only Bookie_3 continues to have a season-long record on line betting significantly above 50%.

All the Head-to-Head Probability Predictors turned in yet another round of positive probability scores making it three-in-a-row for all of them and eight-in-a-row for the TAB Sportsbet bookmaker.

The Line Fund algorithm turned in a slightly sub-zero performance and now has a -0.029 average probability score across the season, still good enough to have yielded a 6.1c gain for the Line Fund.