PDA

View Full Version : average odds

transylvania
12th January 2010, 05:39 PM
Hi all! did anyone have a clue how betfair is working out the average odds, for example if you got matched one selection at 12.5 and 1.05 whats the average odds?

The Geek
12th January 2010, 05:56 PM
I suspect it goes something like this.....

If you get £2 matched @ 12 & £5 matched @ 1.05...

Stake * Price
2 * 12 = 24.
5 * 1.05 = 5.25.

24 + 5.25 = 29.25.

Divide 29.25 by original stake = 4.18.

However, what I have discovered is that in very rare cases the average odds are returned incorrectly, so they can not be relied on 100% { TT had an obscure hedging bug up until a couple of months back that was caused by this.}

transylvania
12th January 2010, 06:11 PM
thank you very much for your reply, in my case i working on book and i find out that 12.5+1.05 the average is according to betfair 7.51 my calculator is saying 6.77 , so something im missing or just me.
thanks

nigelbleddfa
12th January 2010, 06:27 PM
thank you very much for your reply, in my case i working on book and i find out that 12.5+1.05 the average is according to betfair 7.51 my calculator is saying 6.77 , so something im missing or just me.
thanks

Have you staked equal amounts on each bet ? If you have, the average odds would be 6.

( 12.5 - 1) + ( 1.5 - 1 ) /2 = (11.5 +0.5 ) /2 = 12/2 = 6

rockaren
12th January 2010, 07:38 PM
Have you staked equal amounts on each bet ? If you have, the average odds would be 6.

( 12.5 - 1) + ( 1.5 - 1 ) /2 = (11.5 +0.5 ) /2 = 12/2 = 6

why is there (1.5-1) ?

doubleback
12th January 2010, 08:04 PM
The stakes are important and can effect the average odds, i would work it out like this:

Bet 1 = Odds * Stake

Bet 2 = Odds * Stake

(Bet 1 + Bet 2 ) / Total Stake = Average Odds.

nigelbleddfa
12th January 2010, 08:32 PM
why is there (1.5-1) ?

Sorry ! My answer is correct but I have converted the sum to conventional odds, so my answer = 6/1.
To get Betfair odds add 1, so Betfair odds = 7

Temujin
13th January 2010, 05:22 AM
If:
Each stake was equal, and the matched odds are accurate, then 6.775 is the average odds.

What you have to remember though, is that things get rounded off. 1.05, you may have actually averaged 1.054999999999, which is rounded down to 1.05 for visual purposes.

I suspect though, that you had a bigger stake on the 12.5 to get a higher figure for your average odds. Not as simple as just (odds + odds)/2, unless your stakes are equal, and price matched is exact.

Temujin
13th January 2010, 05:25 AM
Sorry ! My answer is correct but I have converted the sum to conventional odds, so my answer = 6/1.
To get Betfair odds add 1, so Betfair odds = 7

You actually make a false assumption. Your answer is not at all correct, unless you aren't answering the OP question, but your own.

Odds matched were 12.5 and 1.05. Not 12.5 and 1.5.

nigelbleddfa
13th January 2010, 09:09 AM
You actually make a false assumption. Your answer is not at all correct, unless you aren't answering the OP question, but your own.

Odds matched were 12.5 and 1.05. Not 12.5 and 1.5.

Yes, sorry, you are right. I misread the original question. Probably due to a mental block which tells me never to back at 1.05.

birinhos
16th August 2011, 02:45 PM
I have made a java function to do this but for the example : 2@12.5 and 5@1.04 , the answer that my function gives is 4.3 (betfair odd).

for this example (2@12.5 and 5@1.04) what is the correct answer ?