Wouldn't the percentage still be the same even if it was gambler betting on sports because in sports there are so many surprises with unexpected results such as the winning of the underdog team.
I fond of sports betting and know some people who really only want to bet on every football match, from personal experience and the perspective of the people around me it can be concluded that sports betting has percentage make money of only 50% and the rest is chance of lost.
What better about sports betting is that we can find and create our own opportunities depending on how we have the knowledge and how to analyze to predict the results to determine the betting options.