Sunday, 22 January 2012

Proddabilities

Two big games in England today, and there's something a little odd about the Arsenal v Manchester United Unders price. As you all know by now, my spreadsheet calculates the probabilities of each score combination, and from that the Match Odds and any market I'm interested in. My Match Odds are (H/A/D) 3.01 / 2.56 / 3.61 and on Betfair the mid-prices are 3.025 / 2.57 / 3.575 - could hardly be closer, but my Under 2.5 price is 1.74 while 2.17 is available - a whopping 24.7% edge. If the market has a higher goal expectancy than I do, then why are the draw odds not higher? Opportunity knocks.

The Manchester City v Tottenham Hotspur game also has prices close to mine, including the Under where I have 2.13 against 2.17 available. Home I have 1.87 (1.925), Away 4.33 (4.55), Draw 4.18 (3.825). Not much value there.

3 comments:

gundulf said...

Interesting Cassini. With no mathematical insight from yours truly my read of the game is that the Gooners will want 'revenge' for that small beating they took earlier in the season. My gut feel for the match, for what it's worth, is (dare I say it) that the market has got it right with respect to the 2.5 at least.

I suspect that the prices for Match Odds and the discrepancy you detect between unders and the draw is due to good old fashioned 'fan money' and as such has little mathematical correlation. Home win for me.

BigAl said...

Your numbers aren't making the much discussed draw adjustment. Off your supremacy and total goal inputs, your adjusted draw price should be more like 3.30.

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