QB first reads the defense on dropback. If the defense is running a Cover 2, delayed Cover 2, Man 2, double coverage on one side of the field, or a chicken sandwich, the QB then proceeds with the next read, which is to check the trigonometric angle between Receivers A, C and the nearest safety. If this angle is < 15 degrees (or < 18 degrees if the game is played below Latititude 35 degrees), and the defense is blitzing more than 4 players, you throw to receiver A. Otherwise, you have to calculate the weakside linebacker horizontal trajectory to determine if the pass goes to receiver B or C.

If the defense is running a Cover 3, quarters, Cover 1 Robber, or Punt Defense formation, you have to use basic calculus to get the slope of Receiver C's route and combine it with the summation of all linebacker and safeties momentum vectors to determine if you lob a bomb to Receiver B or dump it off to Receiver C.

Also, if your reads take longer than 2 seconds, you are in trouble.