Ignoring the price.
“Who will win?” and “Is this a good bet?” are different questions.
The favorite can be very likely to win and still be a poor deal at the payout offered. Picking the winner isn’t enough if the wins pay too little to cover the losses.
Imagine a bet with a true 80% chance of winning. You risk $10 to make $1 in profit.
Across ten bets like that, the average would be eight $1 wins and two $10 losses: $8 won, $20 lost.
You would be right most of the time and still lose money on average. Actual results over ten bets could be very different.
In real sports, you don’t know the true chance so neatly. Your estimate might be wrong, and what you know about a team may already be reflected in the price.
Sources & further reading
- Mean, expected value, and standard deviation
OpenStax. Definitions and worked examples for averages and variation in random outcomes.
- Structural characteristics of fixed-odds sports betting products
Newall, Russell & Hing, 2021. A review of features including in-play betting and complex bets.
Examples on this page are illustrative.