It has some random number in memory up to that maximum amount when the counter crosses the threshold, it pays out, and then resets again to another secret random amount.
Depending on the machine, either coin-in (usually) or wins awarded (the old WMS style) would push that counter up. There's 1-3 counters with a dollar amount and say 'must award by $X.00'. There's no secret to this, a lot of people myself included hunt them.
Older games may not list this but all the new ones do that I've seen.Īn +EV trick is in progressive 'must hit by' awards.
The coin basket visual, as he mentioned, has absolutely no bearing on when it will pay out it's just for show and a red herring.