;)
Sunday, September 16, 2012 at 2:50PM | Post a Comment For the 5th consecutive season the four teams participating in the Preliminary Finals are the teams from ladder positions 1 through 4 as at the end of the home-and-away season.
Sunday, September 16, 2012 at 1:31PM | Post a Comment It's legitimate now, I think, to feel aggrieved by our run of outs on SuperMargin betting. Our two wagers this weekend missed by just 1 and 4 points, meaning that the current sequence of 36 losses in a row now includes 6 losses by less than a goal and 2 more of only single digit proportions. Across the entire season we've now missed 14 SuperMargin wagers by less than a goal and 21 by fewer than 10 points. Small wonder then that the Margin Fund is down by 80c on the season, making it responsible for 16c of the 19c that Overall Portfolios have lost this year.
Wednesday, September 12, 2012 at 8:11PM | Post a Comment Again this week the Line Fund has taken one look at the starts the home teams are being forced to give by the TAB Bookmaker and has opted to keep its - well, our - money in its pocket. The Head-to-Head Fund, meantime, likes the prices that this same Bookmaker is offering for the Crows and the Pies head-to-head, and the Margin Fund is willing to put money, at $7.50, behind its predictions of narrow wins by both home teams, so Investors nonetheless find themselves with plenty to be concerned about on Friday and Saturday, regardless of the Line Fund's indifference.
;)
These two pair of wagers, of similar size at similar prices and in the same SuperMargin buckets in both games, make for a Ready Reckoner that looks like the result of a poorly-funded and oddly-directed cloning project.
;)
The various Tipsters and Predictors all agree that the Crows and the Pies should be favourites, though the Predictors vary considerably in terms of the level of confidence with which they hold this view. Amongst the Margin Predictors, Win7, for example, thinks that the Crows will win by almost 5 goals, while Combo_NN1 feels they'll win by only slightly more than a single goal. Amongst the Head-to-Head Probability Predictors, the TAB Bookmaker (implicitly) rates the Crows as about 59% chances, while WinPred rates them as 85% chances.
;)
In the other game, Win7 is again the home team optimist, tipping the Pies to win by 17 points, with Combo_NN1 this time the home team pessimist, tipping them to win by only a single point. WinPred and the TAB Bookmaker are once more the book-ending Probability Predictors, rating the Pies as 74% and 55% chances respectively.
The Line Fund algorithm rates both games as near coin-tosses once the handicaps are factored in, which is why it's opted to refrain from wagering once again this week.
;)
On the right is a table that summarises the calibration of the Line Fund algorithm's probability assessments for each team so far this season. It provides the average probability score for all the games in which a team has been a participant, either as the home or as the away team, and is calculated for a particular team as 1+log(Prob(Team Wins on Line Betting)) when the team wins on line betting, and as 1+log(1-Prob(Team Wins on Line Betting)) when the team loses on line betting. In both cases, the logs are calculated to the base 2, so the unit of the probability score measure is bits.
With this method of calculation, attaching a probability greater than 50% to a team that wins on line betting will result in a positive probability score, and attaching a probability less than 50% to a team that wins on line betting will result in a negative probability score.
I've highlighted with a dark border those four cells that are relevant to this week's contests and, on the basis of this, now feel more comfortable that the Line Fund has opted to pass on this week's wagering opportunities. It's clear that the Line Fund has done poorly so far this season is assessing the chances of Adelaide and Collingwood on line betting when playing at home, and on Fremantle and West Coast when playing away from home.
(But, logically, if the Line Fund's been poor at assessing the chances of these teams in these circumstances, then maybe we should be wagering when the Fund says we shouldn't ...)
To me, it's interesting to note that there is no team this year for which the Line Fund has a positive average probability score when playing home and away, but seven teams for which the Fund has a negative average probability when playing home or playing away. As well, there are only seven teams for which the overall average probability score, home and away, is positive, and none for which the average is above 0.04. It's also very clear that the Fund has generally struggled to assess the chances of the Crows, Blues, Dees and Port on line betting.
Monday, September 10, 2012 at 8:52PM | 2 Comments Eight teams were in action in Week 1 of the Finals, and eight teams changed positions based on MARS Ratings, including the Saints and the Blues who didn't even set foot on the park but nonetheless climbed one spot each thanks to losses for the teams that were immediately above them.
;)
Hawthorn now find themselves 19 Ratings Points (RPs) clear of Sydney who, in turn, find themselves over 10 RPs clear of the next remaining finalist, the Eagles. Next come the Pies a further 4 RPs back, then (skipping the non-finalist Saints) the Crows almost another 4 RPs adrift and, lastly, Freo, yet another 4 RPs behind. All told, the RP gap between the highest-ranked and lowest-ranked teams now stands at a cavernous 43 RPs. Small wonder then that a Hawthorn v Sydney Grand Final is now priced at better than even money.
(Note that I'm no longer using the Colley, Massey or ODM Systems to rate or rank the teams as the scripts I've written for those Systems are based on there being, at most, a single pair of home-and-away fixtures for any pair of teams.)
Sunday, September 9, 2012 at 7:43PM | Post a Comment In Week 1 of the Finals we saw 1st defeat 4th, 3rd beat 2nd, 7th topple 6th, and 5th triumph over 8th.
;)
In the context of AFL history since 2000, two of those results are relatively surprising. The Swans' victory over the Crows is only the third instance of 3rd beating 2nd recorded in that 13-season period, and Freo's win over the Cats is, similarly only the 3rd occasion on which the team finishing 7th has ended the season for the team finishing 6th.
The Hawks' victory over the Pies is less historically incongruent, with minor premiers having won two-thirds of their contests over teams finishing 4th over the past dozen seasons before this one. In 5th versus 8th clashes, which this year pitted the Eagles against the Roos, the Eagles' huge win over the Roos served only to tip the scales in favour of teams finishing higher up the ladder by 7 wins to 6, so you couldn't really claim that any ascendency had been established prior to this season by teams from either ladder position.
;)
Looking ahead to next weekend, we have the team finishing 2nd on the ladder taking on the team finishing 7th for the first time this millenium, and the team finishing 4th up against the team finishing 5th for the sixth time, such contests having previously finished badly for the team finishing 5th on every occasion.
Generally, teams from the top half of the final 8 have had a far better time in Semi-Finals than have teams from the bottom half, the combined record of teams finishing 1st through 4th now standing at 22 wins and only 2 losses.
Looking at the performance of teams from each of the eight ladder positions that entitle a team to participate in September, we find that the overall performance of teams finishing 1st or 2nd far exceeds that of teams finishing in any other position. Teams finishing 1st or 2nd have won over 70% of the Finals in which they've played in the period 2000 to now, and have progressed to the Grand Final on nine occasions, winning five each. Between them, therefore, they've won 10 of the 12 Grand Finals so far decided in this millenium.
;)
The only other ladder position from which a team has come and subsequently grabbed the Flag is 3rd, and this has occurred only twice. Teams finishing fourth have made it as far as the Preliminary Finals on 10 occasions and have ventured to the Granny only twice, losing on both occasions.
No team from ladder positions 5th through 8th has, as yet, made it to a Grand Final and, in fact, amongst these teams, only two of them, both having finished 6th, have progressed beyond the Semi-Finals.
Details of the progression of the Finals over seasons from 2000 to the present appear in the following table, from which you can see that:
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