odds based on win/loss

Question

First off let me apologize. I'm not good at math. :( That being said, I've got a game I'm building. Basically like horse racing. In the game, you choose 1 of 3 racers and use that racer to play. Now, I think that this basic system would give me a 2:1 odds ratio (1 positive outcome versus 2 negative outcomes). If I were to keep track of wins, losses and total races run, how would I come up with more accurate odds? I know I can calculate the winning percentage, but what would be the formula for the odds themselves?

Answer 1

The win depends only on the choice of the fastest horse. Thus, you can't give more accurate odds than 2:1.

Answer 2

You are asking, that with the data collected, how to change the winning $\%$ of "your" horse to odds.

Suppose the winning $\%$ is $60$, then in $100$ races you'd expect to lose $40$ and win $60$

The odds against are just 40:60, which reduced, would become $2:3$