Very quickly the bet size increases. Is there any scientific and viable reason why red would spin next? No. And even if there was, this strategy certainly doesn’t consider it. Simply the odds of red and black spinning are always the same. It doesn’t matter even if you had 100 blacks in a row. The odds of red or black spinning next don’t change. Intermediate players may understand this, but they are stuck thinking that eventually they are due to win. The fact is eventually you will win, but this doesn’t mean you will profit. Why is explained below.
On an American wheel, there are 38 spots: numbers 1-36, plus 0 and 00.  Your odds of winning a one-number bet are 37 to 1 (37 ways to lose, 1 way to win).  But if you win, the casino doesn't pay you 37 to 1, they pay you less: 35 to 1.  The difference between the true odds and what they actually pay you is 2/38, or 5.26%.  You can do this same calculation for the other bets, and it comes out the same.