The NFL Game Data Prediction Game is a recreation of the game as run by FiveThirtyEight and designed by Jay Boice and Aaron Bycoffe. After launching the game in the 2017 NFL season and running it again in 2018 and 2019, FiveThirtyEight elected to not continue it. Having missed it, it's been recreated here on NFLGameData.com starting with 2021.

Participants predict not only which team is going to win each NFL game, but how likely that team is to win the game, expressed as a percentage. The more confident your prediction is, the more points you'll get when you're right, but also the more points you'll lose if you're wrong. A leaderboard tallies standings across the entire season.

Signing Up

Participants must sign up by clicking "Sign up with Twitter" in the upper-right and authorizing the NFL Game Data Prediction Game app with their Twitter account. Twitter accounts are free to create on Twitter's website using an email address or phone number.

NFL Game Data uses only "read" Twitter permissions. Authorizing the NFL Game Data Prediction Game does not enable NFL Game Data to tweet on your behalf, edit your profile, make changes to your account, or in any way "act as" you on Twitter.

The only data stored by NFL Game Data that is provided by Twitter is your Twitter ID, display name, screen name, whether or not your account is verified, the URL used by Twitter for your profile picture, and tokens used for subsequest authentications. NFL Game Data is never sent by Twitter and never stores your email address or phone number, or the content of any private messages. Some additional information such as your Twitter account creation date and most recent tweet is incidentally sent to NFL Game Data by Twitter as part of confirming your authorization and collecting the stored information, but NFL Game Data does not store or use this information.

This is NOT gambling. There is no entry requirement assocated with participating, and there are no prizes or rewards for participating or performing well. It is for entertainment purposes (such as bragging rights) only.

Making Predictions

For each game, participants use a slider to select the win probability of both teams, expressed as a percentage. Participants can only use whole percentage integers, finer levels of granularity are not accepted. As you move the slider, the numbers to the left and right will adjust to show how many points you will lose or gain based on the winner of the game.

Note that you are making a prediction on who will win the game "straight up". This is not a pick against the spread. Only the win or loss outcome affects your score. The margin of victory has no impact.

A participant may make or change their prediction for a game any time between the completion of the previous week's NFL games and that game's start time of the game in question.

Scoring Rules

The following formula - as used in FiveThirtyEight's version of the game and is a transformation of Brier scores - is used to calculate how many points you score for a game:

In this formula, P represents the percentage number you put for the team you thought was most likely to win, and R represents the result of the game as 0 if that team lost and 1 if that team won. M represents a multiplier which is 1 for regular season games, 2 for wildcard playoff games, 3 for divisional playoff games, 4 for conference championships, and 5 for the Super Bowl.

For example, a prediction of 50% will result in 0 points scored, regardless of the game's outcome. A prediction of 100% in a regular season game will result in +25 points if that team wins the game, and -75 points if that team loses.

Participants' scores for each game are added up across the season to determine their total score for the leaderboard. A participant who does not enter a prediction for a game will score 0 points for that game, the same as if a 50% prediction was made.

Games that go into overtime will be scored by who wins in overtime rules. If a game results in a tie, no participants will gain or lose any points for their predictions for that game.

The two differences between this scoring system and that of FiveThirtyEight's are that FiveThirtyEight rounded scoring to the first place after the decimal (while this version rounds displays to the same level but calculates them further on the backend) and FiveThirtyEight used a multiplier of 2 for all playoff games.

Market

Market plays automatically, adjusting its picks up to game start based on vig-removed moneylines from sportsbooks as scraped by NFL Game Data.

Market's current prediciton will be shown on the Picks screen as you make your own predictions. However, Market can change its prediction right up until the scheduled game start, and will do so as odds change. This means the prediction you see for Market when you make your prediction may not be its final one.

Remember that Market is based on removing the vig, so even if you are higher than Market on the leaderboard, real sportsbooks charge a vig so this does not necessarily indicate you would be a profitable better. If you separately choose to bet, so do only legally and reponsibily.

Leaderboard

All participants will be listed on the leaderboard in ranked order along with their rank number and total points. You may also click a participant to be linked to their twitter account to read their tweets (if not a private account) and choose to follow them if you so desire.

Each participants final prediction for a given game will be available on Github following that game's conclusion. Note the stored number there is the participant's estimate for the home team to win. To calculate points from this number, use the same formula as above but instead R has a value of 0 if the away team wins and a value of 1 if the home team wins.

Rescheduled and Relocated Games

• If the game changes date, time, or location, but is still part of the same NFL week, then participants' last predictions for the game will remain in the system. Participants are of course free to change their prediction if they do desire based on the scheduling update, as long as this is done by the (new) scheduled start time of the game.
• If a game is moved to a different NFL week, then predictions for the game will be reset to 50% for all participants, and predictions will need to be (re)entered to score once games for the new NFL week are available.
• If an NFL game is forfeited or cancelled and does not occur, no participants will score points for that game.

Disputes and Technical Issues

Under no circumstances will game outcomes be scored differently than the official outcome of the NFL as defined by NFL and game officials, even if a clear officiating error can be demonstrated.

Games lock based on the NFL Game Data server time hitting the scheduled start time, not literally when the kickoff occurs in real time. Disputes based on this discrepancy will not be addressed, and predictions will stand as entered before the server locks entries.

In the event of a technical issue or other dispute, reach out to Lee Sharpe on Twitter. He will make the fairest judgment possible based on the totality of the circumstances.

Have fun!