Well fortunately for you I do have a degree in mathematics and am also a professional player so I can help you out! My approximation was of course, just that - an approximation. However, most people, fish and regular alike, tend to act more honestly on Axx flops than other flops. Given the assumption (and this is the one that can obviously be rationally debated which is why I am not interested in defending this point) that I am a skilled player and somewhat infrequently being bluffed off the best hand on Axx boards and similarly infrequently bluffing people off better on Axx boards then my W$WSF should correspond ROUGHLY with the frequency of which I had the best hand.

Here you can use a utility like pokerstove. You may not be aware of it, but pokerstove can perform calculations even with one flop card, or in this case an ace. Against a 20% range KK has 61.2% equity on Axx flops, 63.5% against a 30% range, and steadily increasing onward as the range of villain widens.

There are also more interesting issues here. The big one is that this is our 'run down' equity, or equity given all 5 cards. Villains are very unlikely to be able to see all 5 cards most often. I mean any undercards on an A72 rainbow will have around 3-5% equity against KK but will almost always fold so their effective equity is not realized meaning KK's actual effective equity is even greater. I hope this is clear since its somewhat challenging to explain well.

When you add it up 56.9% W$WSF means I'm being bluffed a ton or people are actually outflopping me massively more often than they should be. The unfortunate nature of poker as a player and the incomplete information we have means this is ultimately unprovable either way.

ACTUALLY AS I TYPE THIS THERE IS A SIMPLE MATHEMATICAL MODEL I CAN CREATE TO TEST THIS THEORY. The frequency of an ace on the turn should indicate beyond a doubt roughly how often villain flopped an ace. If villain does not have an ace in his hand then the odds of an ace on the turn are 4/(52-4 (our hole cards) - 3 (the flop)) if he does then the odds are 3/(52-4-3). A surprisingly huge difference of 6.666 vs 8.888 meaning we should be able to again reach statistical significance even with smallish samples! So assuming the turn is dealt fairly, an A on the turn of 6.666 would indicate villain saw the turn with an A 100% of the time, and 8.888% would mean he never had an ace on the flop. Thus we can approximate how often he had an ace in his hand to see the turn, given the frequency of an ace on the turn.

Oooo. I am anxious to run this!