Casino dealers use a number of quick calculations to determine roulette winnings. The dealer starts by determining the number of numbers in the row and column that the ball is currently in.
This is known as the “spot” or “running” number. .
Next, the dealer looks at the bet that was placed on the roulette table. For example, if someone placed a $10 bet on red and black and the ball is currently in the red column, the dealer would subtract 1 from the spot number (in this case, it would be 9) to get their roulette wager.
The dealer then looks at all of the other numbers on that particular bet and calculates how many points they would be worth if they hit. For example, if someone has bet $10 on red and black and the ball is currently in the 4th column, the dealer would add 1 to their spot number (in this case it would be 10) to get their roulette wager and then look up all of the numbers in that particular row and column (4, 5, 6).
If the ball were to come down in any of those numbers, it would pay out as a winning bet.
