Fourth Down Engine

Situation

Away

Home

Who has the ball?

Offense score

Defense score

Quarter

Clock (min)

(sec)

Ball on

Down

Yards to go

Offense timeouts

Defense timeouts

Second-half kickoff goes to

Your call

Optional factors

Weather

Wind: 10 mph Temperature: 45 °F Rain or snow

Stadium

Roof

Altitude

Team strength

Favored before kickoff: Even

OffenseDefense

Kicker

Offense kicker

Weekly game

This week

Every game

Costliest calls

Best gutsy calls

Season so far, by team

Wins given up per 17-game season on confident mistakes (calls where 18 of 20 models agree the coach chose wrong). Read it as a ranking.

Head coaches vs the engine

Confident mistake: a call where at least 18 of the 20 resampled models agree the coach chose wrong. Close calls never count against him.

Wins lost per season: the win chance those mistakes gave away, added up and scaled to a 17-game season. 0.50 means about half a win a year.

Sort by

Kickers — skill and value over a replacement kicker

How it works

Each option (go, field goal, punt) leads to a few possible next situations. A win-probability model, trained on every NFL play from 2014 to 2025, scores each one. The engine weights them by how likely they are: chance of converting × win chance if you convert + chance of failing × win chance if you fail, and the same for kicks and punts. The option with the highest total is the call.

Twenty copies of the whole model were refit on resampled games. The confidence line says how many of them agree. A call with a small edge, or one the copies disagree on, is a toss-up, not a mistake.

Coaches are only charged for a call when at least 90% of the copies agree it was wrong.

Overtime gives both teams the ball, so a tie at the end of regulation is worth about half a win, plus the better team's edge. After a touchdown the engine assumes the scoring team picks the extra point or the 2-point try, whichever helps it more. On 4th & 1 you can say if it is inches or a full yard.

Reading the screens

Optional factors are off unless switched on. Off means an average situation; with team strength off, the teams are equal and the home team gets the usual home-field edge. Tap a factor's name to change it.

Team strength is the pre-game point spread: slide toward the team that was favored. Picking two teams fills it from ESPN; if no line is found, the teams are set even.

Kickers are ranked by make % from 50 yards in neutral conditions.

Win chance after each choice: separate "what ifs". Only the split at the top adds to 100%.

4th Down Duel: pick your call before Get the call. Green = you matched the engine, yellow = half credit on a toss-up, black = a miss. Log the coach's call and send the card.

Weekly game: five of last week's fourth downs. Call each one before the reveal. You score when you match the engine; the coach scores when his real call matched it.

Live game mode reads ESPN's public scoreboard. It is unofficial and can lag, so check the form before you get the call.

Full method, results and sources: white paper · PDF · plain-English deck