How often does a slot bonus hit?

Bonus (feature) frequency is how often a slot's free-spins or bonus round triggers, usually expressed as one in N spins. It's an average, actual gaps between bonuses vary widely, and the bonus's average payout is usually dragged up by rare big hits, so most bonuses pay less than the mean.

Across our Wanted Dead or a Wild study the bonus averaged one trigger every 238 spins (measured over 370,207 triggers), but that's an average, and real gaps swing far above and below it. The payout side is where players get misled: on Book of Dead the bonus paid a median of about 44x stake versus a mean of about 81x (payouts a model-based estimate; the trigger rate is a single-tracker low-confidence input). The mean is inflated by rare large hits, so a typical bonus pays well under the average.

When a slot advertises a big average bonus, the median is the number that matches most sessions.

FAQ

Can I predict when a bonus is due?

No. Triggers are independent and random; a long gap doesn't make a bonus more likely on the next spin.

Why did my bonus pay so little?

Because the average is skewed by rare big wins, so a typical bonus lands near the lower median. Most bonuses land near that lower figure.

run your own experiment in the simulator

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