Game Cadence

If you were to consider each quarter of football as a separate contest, what pattern of wins and losses do you think has been most common? Would it be where one team wins all 4 quarters and the other therefore losses all 4? Instead, might it be where teams alternated, winning one and losing the next, or vice versa? Or would it be something else entirely?

The answer, it turns out, depends on the period of history over which you ask the question. Here's the data:

So, if you consider the entire expanse of VFL/AFL history, the egalitarian "WLWL / LWLW" cadence has been most common, occurring in over 18% of all games. The next most common cadence, coming in at just under 15% is "WWWW / LLLL" - the Clean Sweep, if you will. The next four most common cadences all have one team winning 3 quarters and the other winning the remaining quarter, each of which such cadences have occurred about 10-12% of the time. The other patterns have occurred with frequencies as shown under the 1897 to 2009 columns, and taper off to the rarest of all combinations in which 3 quarters were drawn and the other - the third quarter as it happens - was won by one team and so lost by the other. This game took place in Round 13 of 1901 and involved Fitzroy and Collingwood.

If, instead, you were only to consider more recent seasons excluding the current one, say from 1980 to 2008, you'd find that the most common cadence has been the Clean Sweep on about 18%, with the "WLLL / "LWWW" cadence in second on a little over 12%. Four other cadences then follow in the 10-11.5% range, three of them involving one team winning 3 of the 4 quarters and the other the "WLWL / LWLW" cadence.

In short it seems that teams have tended to dominate contests more in the 1980 to 2008 period than had been the case historically.

(It's interesting to note that, amongst those games where the quarters are split 2 each, "WLWL / LWLW" is more common than either of the two other possible cadences, especially across the entire history of footy.)

Turning next to the current season, we find that the Clean Sweep has been the most common cadence, but is only a little ahead of 5 other cadences, 3 of these involving a 3-1 split of quarters and 2 of them involving a 2-2 split.

So, 2009 looks more like the period 1980 to 2008 than it does the period 1897 to 2009.

What about the evidence for within-game momentum in the quarter-to-quarter cadence? In other words, are teams who've won the previous quarter more or less likely to win the next?

Once again, the answer depends on your timeframe.

Across the period 1897 to 2009 (and ignoring games where one of the two relevant quarters was drawn):

• teams that have won the 1st quarter have also won the 2nd quarter about 46% of the time
• teams that have won the 2nd quarter have also won the 3rd quarter about 48% of the time
• teams that have won the 3rd quarter have also won the 4th quarter just under 50% of the time.

So, across the entire history of football, there's been, if anything, an anti-momentum effect, since teams that win one quarter have been a little less likely to win the next.

Inspecting the record for more recent times, however, consistent with our earlier conclusion about the greater tendency for teams to dominate matches, we find that, for the periods 1980 to 2008 (and, in brackets, for 2009):

• teams that have won the 1st quarter have also won the 2nd quarter about 52% of the time a little less in 2009)
• teams that have won the 2nd quarter have also won the 3rd quarter about 55% of the time (a little more in 2009)
• teams that have won the 3rd quarter have also won the 4th quarter just under 55% of the time (but only 46% for 2009).

In more recent history then, there is evidence of within-game momentum.

All of which would lead you to believe that winning the 1st quarter should be particularly important, since it gets the momentum moving in the right direction right from the start. And, indeed, this season that has been the case, as teams that have won matches have also won the 1st quarter in 71% of those games, the greatest proportion of any quarter.

Will Investors Be Having A Port Whine on Sunday?

Stakes At Stake

Once again this weekend most Investors will find themselves disproportionately concerned about the outcome of a single contest.

Whilst it'll still be possible for a petite profit to be made should Port fail to topple the Hawks at Football Park, a truly memorable weekend will only be had if the upset eventuates.

To the details then.

New Heritage has 4 bets adding up to a little over one-third of the Fund, amongst them a 13.4% wager on the Dogs at a price not statistically significantly different from money back. They're at $1.02. The riskiest bet amongst the New Heritage clutch is 0.7% on Port Adelaide at $2.65. Every Fund has a wager on Port Adelaide this week, which is why Investors care so much about the outcome.

(Speaking of the use of 'clutch' as a collective noun for wagers, a visitor to the MAFL Online website this week arrived having searched on the phrase "clutching betting" using Google. Quite what he or she was truly looking for I'm as yet unable to fathom, but the length of the visit - 0 seconds - suggests he or she didn't find it on the MAFL Online site.)

Prudence has 5 bets totalling about 20% of the Fund. Its largest is also on the Dogs, 7.2% in its case, and its riskiest is 1.5% on Melbourne at $3.30.

Hope has just 2 wagers. Its largest and riskiest wagers is 5.7% on West Coast at $3.30, and its other wager is also on an underdog: 4.48% on Port Adelaide.

Line Redux has a record-equalling 5 wagers this weekend, 3 on teams receiving start and 2 on teams giving start.

Chi-squared is supporting a dog again this weekend, though whether it's yet another mongrel dog or merely an underdog is yet to be determined. He has 15.6% on Port Adelaide. The evidence does not bode well for this wager given the data in the table below, coupled with the knowledge that he's tipping Port Adelaide by just 3 points.

As you can see, he's 0 from 5 for wagers on teams that he's tipped by 4 points or fewer. Still, based on the wisdom of (generally near-broke) gamblers, I guess that makes him 'due'.

Ready Reckoner

This weekend's Ready Reckoner looks remarkably like this:

For the first time since Round 12, no Investor has an interest - at least on MAFL grounds - in the Friday night fixture. Saturday is, however, moderately important to everyone but MIN#002, and Sunday is screamingly important to everyone except MIN#017.

Tip-top Tipping

On tipping we have no unanimous favourites this week. Here are the details:

* Carlton are 10-3 favourites over the Roos. None of the top 5 tipsters is siding with the Roos.

* The Dogs are 8-5 favourites over Fremantle. Freo's only support amongst the top tipsters comes from STM II, who did tip Essendon to beat Hawthorn at $5 in Round 7, but surely can't be expected to prevail on a team currently at $11.

* Geelong are 10-3 favourites over Adelaide. Amongst the top tipsters only Shadow favours Adelaide.

* St Kilda are 12-1 favourites over Sydney, with Sydney's sole supporter being HSH.

* Collingwood are 7-6 favourites over Brisbane. The Lions count Shadow and STM II amongst their supporters.

* Richmond are 10-3 favourites over Melbourne, though the Dees do have Shadow's and Silhouette's vote.

* Hawthorn are 8-5 favourites over Port Adelaide. Port have a majority of the top 5 tipsters selecting them, however, as Shadow, Silhouette and STM II have lined up behind them. ELO is tipping the Hawks, but only by 4 points, making this its Game of the Round.

* Essendon are 12-1 favourites over West Coast. Once again HSH finds itself in the lonely part of the tipping convention. Chi, though, is tipping the Dons by just a point, making this his Game of the Round.

A Fine Line

On line betting this week, Chi and ELO are of one mind (though I suspect Chi's not contributing much to that entity). They're both implicitly tipping the Roos, Fremantle, Geelong, Sydney, Lions, Melbourne, Port, and West Coast.

An Honourable (Near) Draw

Investors with the Recommended Portfolio should probably be thankful that they escaped the weekend with just a small loss (0.4%), leaving them still up 4.0% on the season. Melbourne's inability to beat the Swans was the cause of most damage, though the Dons' narrow failure to pip the Tigers didn't help, nor did Freo's inability to cover their 8.5 point spread.

Other Investors lost too, MIN#001 and MIN#015 also only narrowly, and MIN#002 a little more substantially. MIN#017 was the only Investor to show a profit on the weekend. MIN#001 and MIN#015 are now up 7.2% for the season, MIN#002 is up 31%, and MIN#017 is up 38.5%.

Two Funds made profit on the weekend. New Heritage made almost 7% from 5 successful bets out of 6, leaving it ahead by 38.5% on the season, such profit deriving from 50 successful bets out of 66 wagers. Line Redux made 4% from its 2 out of 3 performance, leaving it down just over 1.5% on the season based on 25 successful wagers from 49 bets.

Prudence landed 4 bets from 6 but dropped 1.5% and is now up a little over 12% on the season with a 47 from 63 record. Hope won 1 and lost 1 to drop 4.4% but remains 31% ahead on the season with a 10 from 22 record. Chi-squared landed 3 from 4, but lost the one that mattered and so dropped 8% on the round to move to a loss of 55% on the season due to just 12 successful wagers from 25.

On tipping, BKB had the best performance of the round, snaring 7 from 8 to move to 95.5 from 136 (70.2%), joining Shadow on that score thanks to Shadow's paltry 2 from 8 for the week. Silhouette managed 5 from 8 and continues to lead, now by just 3 tips on 98.5 from 136 (72%).

Chi and ELO both had unremarkable line betting weekends, each bagging 4 from 8.

Chi continues to threaten the 30 points per game Mean Absolute Prediction Error (MAPE) landmark. He's now on 30.2 points per game; ELO's on 28.1 and BKB's on 27.2. As a measure of margin-tipping accuracy, MAPE is a good one, though it is subject to the distorting influence of a view blowout results. A measure that is less susceptible to such results, and one that is therefore preferred by some as a measure of margin-tipping accuracy is the Median Absolute Prediction Error.

For Chi, this measure is 26 points, for BKB it's 23.5 points, and for ELO it's 21.5 points, highlighting just how accurately ELO's been tipping margins this season.

Over on MAFL Stats you can view the latest MARS Ratings and there you'll see that the Saints have grabbed the number 1 ranking from the Cats for the first time this season. Given the Cats' patchy performances over the last month, I think that's probably a fair assessment.

A team-by-team comparison of results also highlights the Saints' superiority, especially against teams higher on the ladder:

In this table results in green are victories and those in red are losses. Where a team is to be played in a future round the details are shown in black. The teams are ordered by current ladder position.

21 Again

Tonight I thought I'd wait a little longer to see if TAB Sportsbet would post the final 2 line markets before I wrote this blog but, as of a little after 8pm, they've not.

The two line markets awaited are those for the Carlton v Collingwood game, on which I don't expect we'll have a wager, and for the Fremantle v West Coast game, on which I expect we will. This week's Ready Reckoner is based on us having 5% of the Line Redux Fund on Freo, probably giving 9.5 points start. I'll confirm this as soon as I can.

Including the assumed Dockers wager, we'll again have 21 wagers this weekend, though Chi-squared's marginally more temperate behaviour means that Investors will have, in aggregate, less money at risk.

New Heritage has 6 wagers totalling about 55.5% of the Fund, the largest being a 12.7% wager on the Lions at $1.13. The other 5 wagers are each sized 9.2% or larger and are on favourites, the longest priced of which is Fremantle at $1.60.

Prudence also has 6 wagers, totalling almost a quarter of the Fund, and also has its largest wager - 6% in its case - on the Lions. Its most speculative wager though is on the Dees and is for 3.1% at $2.40. (The Dees have blown significantly since we placed this bet, which is rarely a happy portent.)

Chi-squared has found 4 wagers totalling a little over 25% of the Fund. It too fancies the Dees - if 14.6% can rightly be labelled merely a fancy. Its 3 other wagers are on favourites.

Hope has just 2 bets this weekend, 4.9% on the Dees at the aforementioned $2.40, and 1% on the Crows at $1.50.

Line Redux has 3 bets (including the prospective Freo wager), all on teams giving start.

Every Fund has wagered something on the Crows this weekend, making them only the second team this year - the other being Sydney - to earn such unamimous wagering support. There's some proverb about eggs and baskets that I can only vaguely recall at this point.

Here then is the weekend's Ready Reckoner:

It's a dark weekend indeed when your fate is in the hands of the Dees, especially when draft picks are at stake.

Next, let's turn to tipping, where we have:

* Carlton 9-4 favourites over Collingwood. Though the Pies have scant support, 3 of their 4 supporters come from amongst our top 5 tipsters in the form of BKB, CTL and Silhouette. ELO tips Carlton, but only by 2 points, making this its Game of the Round.

* Geelong 8-5 favourites over the Hawks. Amongst our tipping elite, only Shadow is on the Hawks. Chi's tipping a Cats victory, but only by 3 points, making this his (only!) Game of the Round.

* Fremantle 7-6 favourites over the Eagles, with CTL, Shadow and Silhouette all tipping the Eagles.

* Brisbane unanimous favourites over the Roos.

* St Kilda, perhaps surprisingly, unanimous favourites over the Dogs.

* Melbourne 7-6 favourites over Sydney, with BKB and CTL the only credentialled tipsters foretelling a Swans victory.

* Essendon 10-3 favourites over the Tigers. STM II stands alone amongst its peers in tipping the Tigers.

* Port Adelaide 7-6 favourites over the Crows, with half of the Crows' support coming from CTL, BKB and Silhouette.

On line betting, assuming Freo give 9.5 points start and Carlton receive 6.5 points start (which, as I type this, is no certainty):

* Chi's on Collingwood, Hawthorn, Fremantle, the Kangaroos, St Kilda, Melbourne, Richmond and Adelaide

* ELO's on Carlton, Hawthorn, West Coast, the Kangaroos, St Kilda, Melbourne, Essendon and Adelaide

Update on Friday morning: Fremantle line wager is confirmed. We're giving only 8.5 start. Also, as expected, no Carlton line bet. New Round Summary now available for download.

July - When a Fan's Thoughts Turn to Tanking

Most major Australian sports have their iconic annual event. Cricket has its Boxing Day test, tennis and golf have their respective Australian Opens, rugby league has the State of Origin series, rugby union the Bledisloe, and AFL, it now seems, has the Tanking Debate, usually commencing near Round 15 or 16 and running to the end of the season proper.

The T-word has been all over the Melbourne newspapers and various footy websites this week, perhaps most startlingly in the form of Terry Wallace's admission that in Round 22 of 2007 in the Tigers clash against St Kilda, a game in which the Tigers led by 3 points at the final change but went on to lose by 10 points:

"while he had not "tanked" during the Trent Cotchin game in Round 22, 2007, he had let the contest run its natural course without intervention"

That stain on the competition's reputation (coupled, I'll admit, with he realisation that the loss cost MAFL Investors an additional return of about 13% for that year) makes it all the more apparent to me that the draft system, especially the priority draft component, must change.

Here's what I wrote on the topic - presciently as it turns out - in the newsletter for Round 19 of 2007.

Tanking and the Draft

If you’re a diehard AFL fan and completely conversant with the nuances of the Draft, please feel free to skip this next section of the newsletter.

I thought that a number of you might be interested to know why, in some quarters, there’s such a fuss around this time of year about “The Draft” and its potential impact on the commitment levels of teams towards the bottom of the ladder.

The Draft is, as Wikipedia puts it, the “annual draft of young talent” into the AFL that takes place prior to the start of each season. In the words of the AFL’s own website:

"In simple terms, the NAB AFL Draft is designed to give clubs which finished lower on the ladder the first opportunity to pick the best new talent in Australia. At season's end, all clubs are allocated draft selections. The club that finished last receives the first selection, the second last team gets the second selection and so on until the premier receives the 16th selection."

So, here’s the first issue: towards season’s end, those teams for whom all hopes of a Finals berth have long since left the stadium find that there’s more to be gained by losing games than there is by winning them.

Why? Well say, for example, that Richmond suddenly remembered what the big sticks are there for and jagged two wins in the last four games, leaping a startled Melbourne in the process, relegating them to position Spoon. The Tigers’ reward for such a stunning effort would be to (possibly – see below) hand Melbourne the sweetest of draft plums, the Number 1 draft pick, while relegating themselves to the Number 2 pick. Now, in truth, over the years, Number 1 picks have not always worked out better than Number 2 picks, but think about it this way: isn’t it always nicer to have first hand into the Quality Assortment?

Now entereth the notion of Priority Picks, which accrue to those teams who have demonstrated season-long ineptitude to the extent that they’ve accumulated fewer than 17 points over its duration. They get a second draft pick prior to everyone else’s second draft pick and then a third pick not that long after, once all the other Priority Picks have taken place. So, for example, if a team comes last and wins, say, four games, it gets Pick #1, Pick #17 (their Priority pick, immediately after all the remaining teams have had their first pick) and then Pick #18 (their true second round Pick). If more than one team is in entitled to Priority Picks then the Picks are taken in reverse ladder order.

Still with me?

Now, the final twist. If a team has proven its footballing inadequacy knows not the bounds of a single year, having done so by securing fewer than 17 points in each of two successive seasons, then it gets its Priority Pick before anyone else gets even their first round pick. Once again, if more than one team is in this situation, then the tips are taken in reverse ladder order.

So, what’s the relevance to this year? Well, last year Carlton managed only 14 points and this year they’re perched precipitously on 16 points. If they lose their next four games, their first three draft picks will be #1 (their Priority Pick), #4 (their first round pick), and #20 (their second round pick); if they win or even draw one or more of their remaining games and do this without leaping a ladder spot, their first three draft picks will be #3, #19 and #35. Which would you prefer?

I find it hard to believe that a professional footballer or coach could ever succumb to the temptation to “tank” games (as it’s called), but the game’s administrators should never have set up the draft process in such a way that it incites such speculation every year around this time.

I can think of a couple of ways of preserving the intent of the current draft process without so blatantly rewarding failure and inviting suspicion and rumour. We’ll talk about this some more next week.

*****

In the following week's newsletter, I wrote this:

Revising the Draft

With the Tigers and the Dees winning last week, I guess many would feel that the “tanking” issue has been cast aside for yet another season. Up to a point, that’s probably a fair assessment, although only a win by the Blues could truly muffle all the critics.

Regardless, as I said last week, it’s unfair to leave any of the teams in a position where they could even be suspected of putting in anything other than a 100% effort.

I have two suggestions for changes to the draft that would broadly preserve its intent but that would also go a long way to removing much of the contention that currently exists.

(1) Randomise the draft to some extent. Sure, give teams further down the ladder a strong chance of getting early draft picks, but don’t make ladder position completely determine the pick order. One way to achieve this would be to place balls in an urn with the number of balls increasing as ladder position increased. So, for example, the team that finished 9th might get 5 balls in the urn; 10th might get 6 balls, and so on. Then, draw from this urn to determine the order of draft picks.

Actually, although it’s not strictly in keeping with the current spirit of the draft, I’d like to see this system used in such a way that marginally more balls are placed in the urn for teams higher up the ladder to ensure that all teams are still striving for victory all the way to Round 22.

(2) Base draft picks on ladder position at the end of Round 11, not Round 22.

Sides that are poor performers generally don’t need 22 rounds to prove it; 11 rounds should be more than enough. What’s more, I reckon that it’s far less likely that a team would even consider tanking say rounds 9, 10 and 11 when there’s still so much of the season to go that a spot in the Finals is not totally out of the question. With this approach I’d be happy to stick with the current notion that 1st draft pick accrues to the team at the foot at the ladder.

Under either of these new draft regimes, the notion of Priority Picks has to go. Let’s compensate for underperformance but not lavish it with silken opportunity.

****

My opinion hasn't changed. The changes to the draft for the next few years that have been made to smooth the entry of the Gold Coast into the competition probably mean that we're stuck with a version of the draft we have now for the next few years. After that though, we do have to fix it because it is broken.

The Differential Difference

Though there are numerous differences between the various football codes in Australia, two that have always struck me as arbitrary are AFL's awarding of 4 points for a victory and 2 from a draw (why not, say, pi and pi/2 if you just want to be different?) and AFL's use of percentage rather than points differential to separate teams that are level on competition points.

I'd long suspected that this latter choice would only rarely be significant - that is, that a team with a superior percentage would not also enjoy a superior points differential - and thought it time to let the data speak for itself.

Sure enough, a review of the final competition ladders for all 112 seasons, 1897 to 2008, shows that the AFL's choice of tiebreaker has mattered only 8 times and that on only 3 of those occasions (shown in grey below) has it had any bearing on the conduct of the finals.

Historically, Richmond has been the greatest beneficiary of the AFL's choice of tiebreaker, being awarded the higher ladder position on the basis of percentage on 3 occasions when the use of points differential would have meant otherwise. Essendon and St Kilda have suffered most from the use of percentage, being consigned to a lower ladder position on 2 occasions each.

There you go: trivia that even a trivia buff would dismiss as trivial.

Who'll Be There in September (Maybe)?

With just 6 rounds to go in the competition, a few articles are emerging about how the teams will fare over the remainder of the season and, most importantly, who'll finish where in the top 8.

Using the MARS Ratings from MAFL Stats I've also predicted the results for the remainder of the season, details of which appear below:



On the right of the table I've provided the game-by-game projections for each team. Green boxes denote victories, red losses, and a bracketed "H", "A" or "N" denote Home, Away and Neutral Ground venues respectively.

If these projections are accurate, there's not a lot of change that we'll see amongst the top 8. In fact, we'll see no change at all in terms of its membership and only a couple of significant changes in terms of its ordering.

Carlton, I'm forecasting, will leap 3 places and secure a top 4 spot, beating Collingwood (currently 4th), the Roos (12th), Port (9th), Melbourne (15th), and Adelaide (6th) in so doing, losing only to the 2nd-placed Geelong in Round 19. This string of results will draw Carlton level with the Lions on 56 points, but will see them grab 4th with a superior percentage.

Collingwood will surrender their top 4 spot, dropping to 6th due to losses to Carlton (7th), Adelaide (6th), and the Dogs (3rd). Victories over the Lions (5th), Richmond (14th), and Sydney (11th) won't be enough.

Port Adelaide and Hawthorn are projected to finish level with the Dons on 44 points but will miss a spot in the eight on percentages, in Hawthorn's case despite finishing the season with a three-game winning streak.