You can join various Leagues on Previse42. Each League is made of Rounds -- prediction contests. You'll get a score for each Round. These scores will be combined into an overall rating for the League.
Each round the user makes predictions by answering simple Yes/No questions. For each question and each user we put 100 points in a pool. When the prediction is resolved, the content of the pool is split between the users who answered correctly. So if a user answers correctly a question that very few other users get it right he will get many points; if many users were right, the user will get less points. Pay attention to the percents of users who predicted Yes/No (displayed under the question)!
For example, say five users answer a question. Two predict Yes and three predict No. 500 points are in the pool at the deadline. Say the prediction is resolved and Yes turned out to be the correct answer. Then the two winners share the pool, each receiving 250 points. The other three users receive 0 points. (checkout the giff on our homepage)
The score of a user in a round is the sum of all points received on all questions.
Users are rated using a system similar to the ELO in chess. When a new user joins a league he receives a rating of 1500 -- about the middle of the rankings. Then the rating evolves. A user with a high rating is expected to rank high, while a user with low rating is expected to rank low. If the user is ranked higher than expected, his rating will go up after the round -- proportional to how much he exceeded expectations; if the user ranks lower than expectation his rating will go down; if the user ranks approximately with the expectation, the rating his rating will stay approximately the same.
The most recent round performances are valued more than the older ones by the system, to hopefully reflect your current prediction skill. Also, if you miss some rounds your rating is not affected:)
After each round, the user receives a badge for her performance in the Round and another one for her new ranking in the League. We hope these badges are funny! Check out previse42.com/legend if you are confused about some badge:).
You can share your badges with your friends and with the world! More you share, more users will join the game and Previse 42 will be more fun to play <3