Welcome to roster.watch prediction game!

This is how the game works:

For each upcoming fight listed on the events pages below, submit your estimated probability of each fighter winning (e.g. 65-35).

After the fights, your predictions are scored using the reversed Brier score. A higher score is better. Scores are calculated as:

Score = (p - o)²

where p is your predicted probability (as a decimal) and o is the outcome (0 if the fighter wins, 1 if they lose).

If you estimate a fight at 65-35, you will score as follows:

(0.65 - 0)² = 0.4225 → 42.25 points if the 65% fighter wins

(0.35 - 0)² = 0.1225 → 12.25 points if the 35% fighter wins

Draws and no contests will not be scored.

It is generally assumed that the optimal way for the best Brier score is to submit what you believe is the true probability for each outcome rather than, say, 100-0 to who you think will win. But feel free to experiment.

In addition to fellow human beings, you will be competing against 4 automated baseline accounts:

• roster.watch Elo: predicts using roster.watch Elo probabilities.
• roster.watch Elo 100%: predicts a 100% win probability for the fighter with the higher Elo rating.
• 50-50: predicts every fight as 50-50.
• User Average: uses the average of all human predictions.