Looks like Gavin has gone for 75% again. I cannot understand why such a low threshold is being used.
Incompetence or malice? Gavin should know better, so flip a coin.
I for one am delighted he's using the optimally bad 75% value.
OrganOfCorti mathed the hell out of the issue until there was no room for doubt.
75% maximizes chances (ie, ensures inevitability) of a premature fork that subsequently orphans the attacking chain.