Wednesday, 16 June 2010

The Swiss Roll

The good news: Queensland beat New South Wales easily enough (34-6) to start the day off on a high note, which was followed by a win for Chile, and then the even better news - the upset of the World Cup with Spain losing to Switzerland and in danger of not winning their group and facing Brazil in the Round of 16.

The second round of group matches is now underway, and perhaps some more open games with a few more goals. It’s hard to imagine there could be any less!

A different Anonymous asks what my ROI is.

I have no idea! Because I am mostly a trader with different styles in different sports, it’s not easy to calculate. Some big events I have close to 100 trades on.

The Premium Charge causes problems too. There’s no easy way to go back and apportion the charge to individual markets from the week before. Seasons overlap so it’s not even viable to calculate it by sport.

Anonymous continues on ROI:

Personally, I aim for 5%. If I make something 50% I won't play at a price under 2.10. If I make something 58% I need 1.81
For my punts on sports such as football and rugby, where I try to use BETDAQ and perhaps WBX, I am similar. If I have a selection rated as a 0.5 probability, I look for at least 2.06 if the commission is 5%, 2.05 if it’s 4%, 2.04 if it’s 3% etc.

He adds:
I tend to feel more confident when I price outcomes between, say, 40-60% which is normally the case when backing handicaps and the like. I would normally look for a slightly bigger edge with more "extreme" numbers.

I view the more extreme numbers as outliers from the majority of the data, and are thus less reliable. Manchester United do not play Exeter City too often. Erring on the side of caution with this type of matches seems entirely reasonable to me.

He asks:
I'd be interested to know how, for example, would you have priced the Germany -0.75 market v Australia?
The question on Germany -0.75 is an example of something for which there is little historical data so the answer is that I wouldn’t be able to price this market up with enough confidence to put anything more than an interest bet on it.

I did have an interest on the Germany -0.5/-1.0 market based on the Elo ratings for these two countries, and using my spreadsheet which predicted a +1 win for Germany, but the spreadsheet was developed for league matches not quadrennial tournaments and so there was a large dose of ‘feel’ associated with this.

A project for the close season is to enhance the spreadsheet to give a precise superiority figure for one team over another. As I wrote before, currently a team can have a +0.5 or a +1.49 superiority, but both are rounded to +1. It should be easy to improve this and use the Asian Handicap markets when they are liquid enough.

In a sign that the League season is approaching, the draw for the first round of the League Cup has been made with newcomers Stevenage Borough drawn at Portsmouth (how the mighty are fallen) and Yeovil Town no doubt delighted at drawing Crystal Palace, who came close to the nightmare of becoming the Diddymen.

1 comment:

Anonymous said...

So basically you're saying you aim for a minimum edge of about 0.5%?? (i.e. taking, after commission, 2.01 on 1 2.00 shot)

That's crazy. There's no way you could price up markets accurately enough to make your perceived 0.5% edge a reality. You would be having non-value bets an awful lot of the time.

I'm not a trader but ROI can be worked out easily enough. On the rare occasions where I do move in and out of a market in running, I use my stake as my maximum exposure at any given time. You should be able to do the same.