The notion of the 15 degree rule is that once the flex is that great it is visible to the naked eye, now who are we kidding, Bird, Malinga, Tait, Akthar, Murali, Botha, Harbhajan might all look dodgy when they are bowling, but get them tested in a bio-mechanics lab and almost everyone of them would come out clear, so i mean what is the point of holding this whole charade, it think it was Warne who suggested that all bowlers should be made to wear a device during the game, that records of degree of their flexes, and tbh as unreal it may sound this is the only fool-proof way of overcoming this problem.