Wednesday, 30 September 2009

Draw Your Own Conclusions

The dearth of draws in the Premier League this season has been a recent topic of much discussion on the Betfair forum. A number of reasons have been posited, some with merit, others without. While this in an interesting phenomena in itself, the really interesting question is that of whether we can make money from this.

A number of people are of the opinion that a lack of draws to date means that there will be more in the future to maintain the long-term average, but this is like saying that after five heads in a row, that tails is more likely on the next spin. There is a name for this - Gambler's fallacy, also known as the Monte Carlo fallacy or the fallacy of the maturity of chances, which is “the belief that if deviations from expected behaviour are observed in repeated independent trials of some random process then these deviations are likely to be evened out by opposite deviations in the future”.

So unless there is a valid underlying reason for why draws are less numerous this season, a reason which is expected to continue to hold true, then we clearly are wasting our time adopting a strategy of blindly backing the draw in the future.

There has been an increase in goals this season, which clearly affects the probability of a game resulting in a draw. Is there a reason for this, or is this just a statistical anomaly?

I believe that there is an explanation for this.

At the start of the season I divided the Premier League into four groups.

A. Big 4 (Arsenal, Chelsea, Liverpool, Manchester United)
B. Europa (Aston Villa, Everton, Manchester City, Tottenham Hotspur)
C. Middlers (Blackburn, Bolton Wanderers, Fulham, Sunderland, West Ham, Wigan)
D. Strugglers (Birmingham City, Burnley, Hull City, Portsmouth, Stoke City, Wolves)

This was somewhat subjective of course, and as the season progresses there may well be reason to revise the groups.

To date, there have been only 10 games between teams in the same group. Three of these matches resulted in draws, and in fact all were close, with only one of these being won by more than one goal (Stoke City’s 2-0 thrashing of Burnley!) I also look to these intra-group games to be low scoring, and indeed, 8 of the 10 have been under 2.5 goals.

Removing these games leaves 56 games between ill-matched teams, just one of which as resulted in a draw. Bolton v Stoke, and these are both teams whose grouping is highly subjective and on a different day may well have been grouped together.

After just 10 matches from 66, this weekend sees no less than five more intra-group games. On Saturday we have Burnley v Birmingham City and Wolves v Portsmouth followed on Sunday by Chelsea v Liverpool and West Ham v Fulham. Finally, on Monday, Aston Villa host Manchester City.

Of the four draws so far, from the 66 games played, not one has involved any team from the top half of the table. Perhaps this is because we have only had one intra-group game in Group A and none yet in Group B? More goals than average – just the result of the way the fixtures have been scheduled.

It might be too much to hope for, but if anyone is laying the draw at a longer price than usual, the four fixtures listed above might be worth a shot. However, as might be expected, the prices on the draw for these games are currently: Burnley v Birmingham City (3.4), Wolves v Portsmouth (3.5), Chelsea v Liverpool (3.55), West Ham v Fulham (3.4), Aston Villa v Manchester City (3.4). Prices for intra-group matches are usually in the 3.4 to 3.6 range, so no sign that the draw price has changed, which is only to be expected.

Unders on these matches are currently 1.73, 1.74, 1.82, 1.75 and 1.96 respectively, but the markets are not yet firmed up, so expect better prices closer to kick-off.

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