Tattersalls calculations

[Guest Whopper73]

Ok, so I'm new to horse racing and I am testing out a system I am filtering from Adrians Masseys tables and I have started to place small bets after convincing myself the system will work :unsure Anyway, I placed a bet that came in today but I didnlt get the expected return due to horses piulling out before the start of the race and I lost 25p in the pound (or at least I think in the pound!) but I cannot work out how the math is done to calculate the adjustment. Can anyone here help? If it any help the stake was for 48p to win (a percentage of a very small bank for proofing purposes - so stop laughing!) with odds of 5.50. The expected return was 2.64, but the actual return was 2.10. Can anyone explain how!!

[Tulenos]

Tattersalls calculations It looks like the 2nd fav (5/2 to 3/1) was withdrawn, therefore deduction of 25 p in a pound according to Rule 4. The deducton is based on the odds of the withdrawn horse not your sel.;)