How do you arrive at these numbers for 1 in 25 and one in 17 for example? Isn't this all in the computer chip and only known by the Mfg.?

As for the Progressive, do any machines still have that? I remember they came out with that and in a few months, the amount was locked at a specific figure.

What hapened? Too many winners.

As for the per strike figure, I would think your extensive play and others who play hours, much be able to get together and come up with an extrapolated figure.

What's difficult to figure in, is all the two coin payouts, that just get added as credits. So in the hypothetical situation, where a player puts in $20 to play and during the session wins two strikes, they would say the strikes cost $20 or $10 each. (remember hypothetical!) But in fact they have won some payoffs during that time, so the actual cost was over $20. You need to include the initial amount, all winnings in between and balance with what's left at the end.

Too much book keeping for a scientific study. So the alternate method.

How much did you start with, how much did you end with, how many strikes... is what we can know.