My guess is coincidence made it look this good, or a number of trials that are not shown, but it could still be done with at least one method I can think of.
Oh my god
I'd hate to see the ones that went poorly!
No I hate to disagree but I really doubt coincidence had anything to do with it. Most people go to great pains to ensure roulette effects are as safe as possible and I am sure he went through even greater pains considering failure would not only threaten his well-being, but the well-being of his volunteers.
No, I was trying to reduce exposure, but coincidence made the two look the same, how I would pull this off is with a variation of a magician's force, coincidence seems to be what made them look the same without saying too much.