if you’re betting ‘2/1’ odds, we basically take a random number from 1 to 100, and if it’s above 50, the house loses, which is another way of saying ‘you win’. If you’re betting ‘4/1’ odds, we take a random number from 1 to 100 again, and if it’s above 75, the house loses, and you win. If the random number is below 75, the house wins, and you lose. If you chose odds of 5/1, your random number needs to be above 80 etc.