What Do Betting Odds Mean?īetting odds achieve three essential things. While many calculators exist out there that can crunch the numbers for you, familiarizing yourself with how lines work is essential to becoming a skilled sports bettor, and focusing on the bets that are worthwhile hold the key to a big win. Ever wondered what the ‘+’ or ‘-‘ means in odds? For those of you looking to learn how to read betting odds, you will find the following guide to be a perfect and detailed breakdown of how odds work, what probability they carry, and how you stand to benefit from this new knowledge.