You need to use a calculator that simulates these scenarios based on variance and bet size to be more accurate.
(Most times you'll bust very quickly and other times you'll hit a big win and wager it all) with the average wagering of £700 your expected value will be about £70. On average you are going to only wager around £700 ish depending on the variance of the slot. This was typically £5 spins if you deposited £100 to get £100 with *30 wagering so £3k wagering requirements then your maths would say on a 96% slot this is -£20 expected value. The strategy is to do as big a spins as you can on high variance slots. High risk casino offers used to be common place but aren't so much now. Sorry but that's not how it works, it is about how much you wager on average.
