What's a good way to rate or compare different predictions for the same event? Suppose I have predictions from 3 sources for the 4 NFL playoff games this weekend. After the games are over and I know who won, what's a good formula for rating each of these sources on the accuracy of the predictions?
Deviation from what? If I understand percent deviation correctly, it's percent deviation = (observation - standard)/standard But what is the standard? For that matter, what is the observation? Suppose Team A plays Team B. Jack gives A 75% odds. Jill gives them 50% odds. Team A wins the game. What is the percent deviation for Jack and Jill?