Two-Minute Drill Game.

Every day you get one real late-game drive from an NFL game, with the real score, clock, ball and timeouts and the players who were on the field. You call the plays, and each one is graded against the best call available in that spot and tallied against 1,455 simulated drives from those same real plays (five kinds of caller, from a coin-flipper to a sharp one). Then you switch sides and call the defence on the snaps the other team runs. Nothing to install and no account to make: today's drive is the fresh one, older ones sit in the archive, and all of it runs in your browser.