Friday, 2 August 2013

0:0 And Gambler's Fallacy

Some free, but not very good, advice seen recently on the Betfair Forum is this:

Lay the 0:0 in the games after a team draws 0:0 with the two teams. So for example Manchester City draw 0 0 with Southampton then lay 0:0 in their following games. Very unusual for a team to get 2 0:0s in a row - outside Argentina that is!
Really? I'd like to see the research on this finding! As something of a (self-proclaimed) expert on the draw, I took a quick look at last season, and the big five leagues and found the following:

Fortuna Dusseldorf and Genoa both had THREE consecutive 0:0s

Bordeaux and Palermo had consecutive 0-0s twice.

In the EPL Arsenal opened the season with two 0:0s. Chelsea, QPR, Everton and Norwich all had consecutive 0:0s.

Freiburg did it in the goal rich Bundesliga and Catania and Undinese had consecutive 0:0s in Serie A.

Bastia, Marseille and Toulouse all did it in France, and Osasuna and Getafe went back-to-back 0:0 in La Liga.

And there may well be others. I have a life you know!

I remember when Tranmere Rovers played five consecutive 0:0s in 1997-98. Not sure if that was a record, but consecutive 0:0s is certainly not 'very unusual' and you should never lay 0:0 solely on the basis that this was a team's previous result. Gambler's Fallacy.

In fact, in my opinion, if a team can't score and is solid at the back, isn't the 0:0 in the next game more likely, not less, all other factors being equal?

For the record, 54 of the 517 matches selected by the XX Draws spreadsheet last season ended scoreless (10.44%) and overall the total has been 172 / 1705 overall (10.09%).


Danny Murphy said...

Great post Cassini.

AL said...

I was backing the 0-0 last season in the prem and suffered some painful long losing runs... mostly near the end of the month.