small red into a big one

just wondering whats the smallest red you have turned into a far bigger one, ie couldnt accept a small red so try to reduce it but ended up making it significantly  bigger.. so the other day laid one in ireland NH flat race " obviously couldnt win " the way it was running .it kept getting backed .i took a £20 red  but as i redded up   it drifted again so i thought i am getting my money back i arent taking a red as it was a grinding day to get my wages and i have traded all day to get that money so i laid it again as it couldnt win " from there " obviously kept laying it way to big it  yes it won  so i turned a £20 red into a £895 red ..ouch.