Cynthia Jay-Brennan The phrase ‘money isn’t everything’ is often used to downplay the importance of money, in a consolatory way, but the old saying was never more aptly illustrated than by the tragic tale of former Las Vegas cocktail waitress Cynthia Jay-Brennan.

On January 26, 2000, at the age of 37, Jay-Brennan invested $27, at $3 a spin, in a ‘Megabucks’ slot machine at the Desert Inn – which closed in August that year and was subsequently demolished to make way for Wynn Las Vegas – and won a record-breaking jackpot of $34.96 million. An infrequent and careful gambler, Jay-Brennan enjoyed living the ‘high life’ for a few short weeks, marrying her boyfriend, honeymooning in Fiji and looking after her family financially.

However, on March 11, during a family visit to Las Vegas, the car in which she and her elder sister, Lela, were travelling was smashed into by a habitual drunk driver, while stationary at traffic lights. Her sister died at the scene and Jay-Brennan was rushed to hospital, where she remained unconscious for several days. When she regained consciousness, she was informed by medical staff that her fifth lumbar vertebra had been shattered, leaving her paralysed from the waist down.

The offending driver was sentenced to serve a minimum of 28 years’ imprisonment, but that, of course, was scant consolation for Jay-Brennan. While thankful to be able to pay her medical expenses, she said, ‘I’d give every cent I have’ to turn back the clock to the days before the accident.

What are the Odds of Winning on Slot Machines? Of course, the odds of winning on a slot machine depend on the probability of aligning a winning combination of symbols. That probability depends, to some extent, on the total number of reels and the total number of symbols on each reel. However, that is not the whole story; the reels of a slot machine are ‘weighted’, such that low-paying symbols and blanks occur more frequently than high-paying symbols. To make matters worse, each reel is weighted differently, such that high-paying symbols are even less likely to occur on reels two, three and so on than they are on reel one.

The weighting for each ‘stop’ on each reel – which, in turn, determines the probability of each winning combination occurring, and the house advantage, or ‘edge’ – is known to the casino, but not to the player. Consequently, in the absence of a so-called ‘par sheet’, which is generally confidential information, the player knows the winning combinations and the payout for each one, but little, or nothing, about the odds of each combination occurring. The fact that the odds of winning are unquantifiable makes slot machines unique among casino games.

If the weighting of each symbol and reel is known, calculating the probability of each winning combination becomes easy. For example, on a three-reel slot machine with 64 stops on each reel, only one of which is mapped to a jackpot-paying symbol, the probability of winning the jackpot is 1/64 x 1/64 x 1/64 = 0.00004 or, in terms of odds, in excess of 250,000/1.

Note that, while a player may not be aware of the odds of winning on any given slot machine, those odds remain constant for each spin. Slot machines are programmed to pay out a percentage of money staked, but the percentage return-to-player (%RTP) displayed on machines in the UK, and elsewhere, is calculated on the basis of playing the machine forever, not for a period of minutes or hours. Consequently, the belief that, say, a jackpot is more likely to hit because it has not done so for some time is fallacy; each spin of the reels of a slot machine is an independent, random event, completely unaffected by past events.

Slot Machine Myths Slot machines blow ‘hot’ and ‘cold’

No, they don’t. The outcome of each spin of the reels is determined by a random number generator – or, at least, a pseudo-random number generator – and is an independent event, completely unaffected by previous events. The odds of winning are determined by the number of reels, the number of symbols on each reel and the ‘weighting’ of each symbol. Weighting information is usually known only to the casino, but the point is that the odds of winning, say, the jackpot, are exactly the same whether the slot last paid out the jackpot on the previous spin or six months ago.

The longer I play the better my chances of winning

Not so. Each outcome is completely random and independent, so the odds of winning are the same however long you play. In fact, the longer you play, the closer you’ll come to the percentage return-to-player (% RTP) figure for the slot in question. % RTP typically ranges between 85% for offline casinos and 96%, or more, for online casinos, but the inherent house edge actually means that the longer you play the worse your chances of winning.

A percentage return-to-player figure of 92% means I’ll only lose £8 of every £100 I stake

No, it doesn’t. The percentage return-to-player (% RTP) is an average, calculated over infinity – or, in practical terms, the lifetime of the slot – and, as such, does not apply to a single gaming session. In the short term, you could win the jackpot, win a little, lose a little or lose £100 for every £100 you stake, so don’t rely on % RTP as an accurate guide to returns.

Casino staff can ‘loosen’ or ‘tighten’ slot machines

No, they can’t. Whether lower than average, high than average or just plain average, the payout ratio of any slot machine is determined by a microprocessor, pre-programmed at the factory. Casino staff can do nothing to change it, one way or the other.