Not sure this helps Mattio

These are some actual figures from a laying system i have been doing.
All were favorites on betfairat sometime in betting

From 20/3/2010 to 20/4/2011

Bets 2013

Accidents 510

Av price 3.7

Laying to liability of $2000

More than 90 % were actually Layed

The balance were all documented(They werent layed because of phone or internet problems)