What Einstein actually meant was that there is no mathematical trick that can help you win at roulette. Each spin is an independent trial and, in the long run, the casino will win. This is different to a game such as Blackjack where the probabilities change as cards are dealt.
Some bets in American Roulette have an even higher house edge than the 5.26% average. For example, a bet on the Five Numbers (0, 00, 1, 2, 3) carries a house edge of 7.89%. Outside bets in roulette carry the lowest risk. They cover more numbers yet the payouts are lower (1/1 for Red, Black, Odd, Even, 1 18, 19 36).