What do the figures on the Race leaderboard mean?

The Race leaderboard displays the following figures:

• OPS: Your overall Obbvio Prediction Score, ranging from 0 to 100.
• T (Total Predictions): The total number of predictions you have made.
• ✔ or C (Correct Predictions): The number of correct predictions you have made.
• A (Accuracy): The percentage of correct predictions.
• O (Average Correct Prediction Odds): The average odds of your correct predictions, which affects the Prediction Difficulty (PD) score (PD = 1 - O).