When I play roulette, I like to be on "repeaters" -- in other words, I bet on whatever number just came in. I am not a mathematician, and I get that the house edge always remains the same, but I am just wondering how one would calculate the odds of hitting a 'repeat' in a reasonable number of rolls.
For example, I know that if 17 just came up, and I bet it again, the odds of it repeating immediately are 1/38. But what are the odds say, of ANY number being immediately repeated in say 20 rolls? Whenever I walk up to a roulette table and look at the screen, it seems there are almost always one or more repeaters there.
Some casino boards show roulette numbers that are "hot" -- given the presumption that several numbers are coming up frequently (i.e., "hot"), it seems very likely that one OR MORE of these "hot" numbers would come up consecutively -- giving rise to the saying "nothing sweeter than a repeater".
So can anyone calculate the odds of some number repeating in any given 20 spins?
The odds of any immediate repeat happening in 20 spins (assuming you count the first number "repeating" if it is the same as the spin right before you started counting the 20 spins) is the same as the odds of any particular number hitting in 20 spins - on a double-zero wheel, this is 1 - (36/38)20, or about 2/3.
I'm not sure you understood my question...let me try wording it a different way... if you walk up to a table and the board shows the last 20 numbers that have come up, how likely is it that in that block of 20 there is some number that came up consecutively?
I know sometimes there will be no repeater ... but some nights I see 3-5 occurrences of SOME NUMBER repeating within the 20 or so that show up on the board.
So if I bet the previous number, I would have won quite a lot...Betting just $5 each time, if there were just 3 repeaters in 20 rolls, I would have spend $100 on those 20 rolls, and won $540. Granted, sometimes I'd lost...but on those times where 5 repeaters are in the group of 20, I'd win $900 for my $100 in bets.
I just am not good enough at math to determine the likelihood of profit betting on repeaters. I do know that my choice of 20 spins was simply due to how many previous spins showed up on the board.
To know whether a profit was likely using repeaters, I guess it matters how often a repeat happen in a typical run of 38 spins...and I'm thinking odds are pretty good that sometime in 38 spins one would see a number repeated. What I would be hoping for is that there would be more than one repeater in 38 spins.
Also note, I am not specifying that THE SAME number keep repeating -- just that ANY number does.
So does that change what you wrote me 3 days ago?