The 'OverRound'

Today I decided to do a little reading at lunch regarding my little gambling hobby. I decided to start re-reading 'Psycho's How to Improve Your Gambling on Horses' and chapter 1 was on the Bookmaker's 'OverRound'.

Now the first time I read this book I was basically overwhelmed by the amount of info thrown at you and the OverRound was a chapter I don't recall in any great deal of depth so it was a nice fresh look at it.

The basic premise of 'The OverRound' is that it's the profit a bookmaker makes on any given race.

Odds are basically the percentage chance a horse has on winning the race. For example:

Fractional Odds of 4/1 = 5.0 in Decimal Odds.

100%/5.0 = 20% Chance of winning the race.

5 Runners Race 'Round' Example:

Horse A - 5.0 Odds = 20% Chance of winning.
Horse B - 5.0 Odds = 20% Chance of winning.
Horse C - 5.0 Odds = 20% Chance of winning.
Horse D - 5.0 Odds = 20% Chance of winning.
Horse E - 5.0 Odds = 20% Chance of winning.

Total Chance of winning the race = 100%

THIS RACE IS PERFECT! IT IS ALSO KNOWN AS A 'ROUND' BOOK.

'Round' books would mean the bookie breaks even. No bookie ever breaks even so they manipulate the odds to make themselves a profit.

5 Runners Race 'OverRound' Example:

Horse A - 4.0 Odds = 25% Chance of winning.
Horse B - 4.0 Odds = 25% Chance of winning.
Horse C - 4.0 Odds = 25% Chance of winning.
Horse D - 4.0 Odds = 25% Chance of winning.
Horse E - 4.0 Odds = 25% Chance of winning.

Total Chance of winning the race = 125%

NOTE: The odds above have been simplified. In reality an 'OverRound' is nowhere near this excessive!

So anyway that is the basic premise of an OverRound. Now it got me thinking about runners decimal odds...

2.0 odds mean the horse has a 50% chance of winning or losing (100/2)

The next step down from here is 1.9 odds which means the horse has a 52.6% chance of winning, i.e. slightly more likely to win than to lose.

So what happens if more than 1 horse has odds of 1.9? We have an OverRound for ourselves!

With a £5 stake:

We win £5.00 from one Lay bet.
We lose £4.50 from one Lay bet.
TOTAL PROFIT = 50p (£5.00 - £4.50)

Then what happens if a third horse has odds of 1.9?

We win £5.00 from TWO Lay bets.
We lose £4.50 from one Lay bet.
TOTAL PROFIT = £5.50 (£5.00 + £5.00 - £4.50)

And so on...

2 horses at 1.9 = £0.50
3 horses at 1.9 = £5.50
4 horses at 1.9 = £10.50
5 horses at 1.9 = £15.50

So of course the next logical step here is to figure out the best races for this strategy to apply to.

My initial thoughts are extremely short flat races where there will be a tight pack of horses, any of which could win; A strategy which I plan to try out in "Test Mode" using Bet-IE.

Watch this space!