Comparison of Slots and Tables

9 July 2020

By John Grochowski

Despite visible differences, slot machines are more similar to table games than most players realize,

Both slots and tables give the house an edge by paying winners less than true odds. Both set odds of the game to drive random results toward an anticipated average, with winning and losing streaks as part of normal probability.

Player can have trouble visualizing all that, or so my email tells me. I’ve explained that random numbers corresponding to slot symbols drive results toward expected averages just as random dice rolls or roulette spins lead toward expected averages.

Jenna, a slot player from the Midwest, emailed with a suggestion.

“Maybe you could put what the random number generator is doing in a table games format,” she wrote. “Maybe if you made up a table game that could also be a slot machine, that would help.”

I’m willing to try, but let’s keep this simple. In craps, there are only 36 possible rolls of two six-sided dice. On a double-zero roulette wheel, there are only 38 numbers.

On a modern slot, there are thousands of combinations – even millions on some machines.

Rather than get everyone bogged down in math, let’s make up the equivalent of a three-reel slot with only 10 symbols per reel.

Let’s set it up as a card game using 7s and fruit symbols, like old-style slots. The dealer has three 10-card decks, and each player gets one card from each deck.

In each deck, there is one 7, two watermelons, three plums and four cherries. That way, after a shuffle, each deck gives you a 1 in 10 chance of being dealt a 7, two in 10 of being dealt a watermelon and so on.

It takes three of a kind to win. Of the 1,000 combinations, only one is three 7s – the lone 7 from each deck. With two melons per deck, you can multiply 2 x 2 x 2 to see there are eight three-watermelon combos. There are 27 three-plum combos, and 64 deals will give you three cherries.

That’s 100 winning combinations and 900 losers – realistic for a three-reel, one-line game.

A random number generator using 10-number sets for each reel would yield the same proportions. If numbers were mapped so that every 1 puts a 7 on a reel, every 2 or 3 shows a melon, every 4, 5 or 6 shows a plum and every 7 through 10 shows a cherry, there would be 1,000 possible reel combinations – one with three 7s, eight with three melons, 27 with three plums and 64 with three cherries.

On a table, let’s say a one-chip bet would bring back 250 chips, including your bet, on three 7s, 40 on each of the eight three melons, 10 on each of the 27 three plums and just one on each of 64 three cherries

Per 1,000 chips wagered, you’d be left with an average of 904 chips for a 90.4 payback percentage or 9.6-percent house edge.

Substituting coins or credits per chips, the percentages would be the same on a slot version with the same paybacks.

The payoffs don’t affect the dealer as he deals the cards. The cards just come out randomly and he makes the payoffs after results are in. The RNG doesn’t know the payoffs as it generates numbers. A different program makes the payoffs after results are in.

You can’t see all that going on during slot play as you can on a table, and slot play is a lot faster than table play. But at their hearts, slots and table games are close cousins.


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