Wait, really? I thought the update said it got better but less predictable, and I vaguely recall hearing that it occurred every 2.5 turns on average. Assuming geometric distribution (i.e. weighted coin flip every turn), that'd suggest a 2/3 chance every turn after the first.
Increased variance, unchanged mean is _not_ better :|
edit: also, to discount the 2-6 turns thingy, I totally saw a run of 9 combats before Jack fired, so...