What is Slot Machine Variance?
The term variance is a mathematical term to explain how far something deviates from the expected value (mean), for example a low variance slot should produce low and regular payouts from the spins and not deviate much from this pattern giving an overall fairly consistent return, whereas a high variance slot will have high peaks and spikes in the wins and often also be referred to as volatile in nature.
Slot Machine Variance
Seasoned online slot players have adopted the term variance and generally group slots into 3 broad categories based on volatility – low, medium and high variance, making it easy to quickly identify a slot machines potential.
In comparison to other casino games such as Blackjack and Roulette even a low variance slot is capable of decent wins multiplied by stake, for example, a very low variance slot such as Bloodsuckers (NetEnt) will be very useful for completing wagering requirements (where allowed) when playing with a bonus, as the expected return to player (RTP) is very high and the variance very low.
A high variance slot can still have a very high RTP (Return to Player) but gives players the opportunity of huge wins from a relatively small stake, what you will generally find is that the slot has been designed so that a bigger proportion of the slots expected payout will be tied into these big wins and/or bonus round features. The medium variance slots will, of course, be the middle ground between both extremes.
The risk of playing high variance slots is much greater, think of it as a risk vs reward decision, if you are looking for wins in the region of 1000+ times your stake then you should definitely be focusing on playing the higher variance slots!
If on the other hand you are looking to extended your playtime then less risky medium and low variance slots are probably what you should be seeking out.