Rivalry match-up

Rivalry match-up is about the fixtures that matter most to supporters. The questions ask who plays whom, and which famous moment belongs to which match-up, from freezing play-off afternoons to last-second finishes that fans still argue about. It suits fans with a season or two behind them best, but newcomers will pick up plenty along the way, because every answer comes with a short note filling in the story. Think of it as a crash course in the grudges that make certain dates on the fixture list feel bigger than the rest.

Playing takes very little effort. There are 8 questions and the quiz lasts about four minutes. Tap the answer that seems right, read the note, then move on to the next question. Nothing is saved to an account, so there is no pressure and no record of any wrong guesses.

The shape of the modern league helps explain why some of these fixtures come round so often. The current layout of eight divisions, each with four teams, dates from the 2002 season, after the arrival of the Houston Texans as the league's 32nd club prompted a full realignment.