Immaculate Grid

This is the American football version of Sports Reference's daily grid. The premise can be summed up in one sentence: nine squares, six criteria around the edges, one player per square who satisfies both its row and column, and nine attempts to achieve it. The criteria mix franchises, such as the Steelers, Eagles, Bengals, Dolphins and Vikings, with statistical categories such as “50+ Sacks career.” The detail that betrays the parent site is in the tooltips: beneath each crest the franchise's successive identities scroll with their date ranges, up to the ephemeral “Phi/Pit Eagles/Steelers (1943).” A permanent note under the board reminds the basic eligibility rule: you must have played a regular-season or postseason game for the team in question.

1. Tap a logo or a category to open its definition; the board explicitly prompts you to do this. That's where the real conditions are.
2. Place one player per square, simultaneously satisfying the row criterion and the column criterion.
3. Manage nine attempts for nine squares; each try is counted, whether successful or not.
4. Check the final result: a score out of nine together with a rarity score.

Sports Reference's grid owes its longevity to the precision of its definitions: when a square says “50+ Sacks career,” the tooltip immediately explains what happens if you cross it with a college or with a franchise, and that rigor removes any argument. The rarity score does the rest, changing the objective: filling the grid is within reach of a knowledgeable fan, filling it with names nobody else picked is a different game. And the crest tooltips, with their defunct franchises and wartime mergers, provide a free history lesson with every round.

The game records two things at the end: how many squares are correct out of nine, and how obscure your answers were, via a rarity score. The rules specify that the game stops at the ninth attempt and that you can then continue to fill missed squares, with those moves not affecting the score. A "Today's Results" link lets you see how you rank among other players that day.

Core play

A single daily puzzle: the game presents one nine-square board (six criteria around the edges) in which you place one player per square who satisfies both its row and column. You have nine attempts for the nine squares; the game records how many squares are correct out of nine and a rarity score. The rules describe this single default daily grid (new each day at 6:00 a.m. Eastern).

• Nine attempts for nine squares means a miss costs you a square on your score, permanently. It's better to start with the intersections you're certain of and save guesses for last.
• Read a statistical category's tooltip before you start: the “50+ Sacks career” tooltip specifies that, when crossed with a college, the performance must have been achieved in the NFL or AFL, not in college.
• The crest tooltips list a franchise's former identities with their dates. A Steelers square isn't limited to the club's modern history, and the 1943 label is a reminder that two franchises once merged for a season.
• A player cannot be used twice: the name that satisfies three squares must be placed where it has no substitute.