So the other day I sent ~51% offence and bounced a CQ, pretty sure I selected CQ and not TM, so the question is what's the minimum % offence required for a potential successful CQ, I'm guessing there is also a random factor involved as to whether the minimum will be successful as you are cutting it rather fine.

Also, what's the least % offence you should send with a 100% guarantee of a successful CQ?

thanks.