Hit frequency

The percentage of spins on a slot that pay any amount — even less than the bet placed. Correlates inversely with volatility:

• Low-volatility slots: 30-40% hit frequency
• Medium: 20-25%
• High: 10-15%

A high hit frequency means the bankroll declines slowly and predictably. A low hit frequency means it declines steadily and rapidly, punctuated by occasional big wins.

Hit frequency is not the same as break-even frequency. Most “hits” pay less than your bet (a €1 bet that returns €0.40 is a hit but a net loss).