What Are Free Spins in a Casino and How They Work
Free spins are either an event in the game's cycle or a promo tool. For reading the game, telling them apart matters.
Free spins come in two kinds, and telling them apart matters for reading the game: an event inside the system, and a casino promo tool.
In-game free spins — an event in the cycle
Triggered by scatters, they're part of the bonus game. For analysis they're not a 'gift' but an event with a date, a distance to it, a bet, a payout and a payout class. The outcome is still the RNG's.
Promo free spins — a retention tool
Granted by the casino, they come with wagering, a win cap and a deadline. That's turnover under conditions, not free money.
How to read free spins as data
Look not at 'they gave spins' but at the path: distance to the event, bet, payout, what the segment closed. Then a free spin is a row in the system, not an emotion.
Bottom line
Free spins change the feeling but not the distribution. It's more useful to see their place in the cycle than to expect a hit from them — same as with signals.