Odds and prices
What is an accumulator bet in gambling?
An accumulator, called a parlay in North America, combines several selections into one bet. Every leg has to win or the whole thing goes.
The prices multiply, which is why the potential return looks enormous, and the margin multiplies too, which is why the book puts an accumulator builder on the front screen of the app.
How the numbers grow
Four legs at 1.91 each multiply to 13.31. A C$10 slip pays C$133 and change. That looks like a good afternoon.
The chance of all four landing at true even money would be one in sixteen, so a fair price is 16.00. You are being offered 13.31. The book's slice went from about 4.8% on one leg to roughly 17% across the four.
Why people keep building them
Small stake, big number. It is the same appeal as a lottery ticket and there is nothing wrong with knowing that is what you are buying.
The problem is when a parlay becomes the default rather than the treat. Legs added for fun are legs priced at the widest margins the book offers, and same-game builders are the widest of the lot because the correlations are priced conservatively in the book's favour.
On the phone
Every app makes adding a leg one tap and removing one two taps behind a swipe. That asymmetry is deliberate.
Check the leg count on the slip before confirming. On a six-inch screen a slip with five legs and a slip with six look identical, and the price will not tell you either.