You are correct, there is no direct reference to roulette in Rock Steady's question. However, if you read the roulette system thread, Mr. J makes a number of points, one being that to win you need an advantage (gambling with an edge), which is what Rock Steady asked about (the edge). My response was based on that.

But it really matters little, for Rock Steady didn't actually state what game (casino, sports betting, horse racing etc) that his stats referred to, for in casino games such as roulette there is always a negative math, while unless arbitraging in sports betting or horse racing there is always only an opinion price.