A streak pass pattern in football is a pass route in which a receiver runs downfield practically in a straight line. Streak routes are long routes that take a while to develop, often aimed at gaining 15+ yards on a catch. Receivers may bob or chop once they get close to the defender to fake them out and create separation. Streaks can also be called go's, straights, or verticals. Some streak routes have specific names. For example, a streak ran close to the sideline is called a fade, and streak routes ran between defensive zones are called seam routes.
Streak routes are great when paired with out routes. They often help set up for a receiver on a shorter route to be open. This is best seen with flood routes. In the most typical flood play, a wide receiver runs a streak, a slot runs a 10-yard out, and a backer or wing runs a waggle. These plays are great for exposing cover three man defenses, in which priority is given to the deepest route, often leaving the 10-yard out or the waggle open.
Seam routes in particular are very useful for offenses facing a zone defense. The idea of the seam is to put a receiver right between two defenders forcing them to choose who covers the receiver. In a perfect defense, the defenders would be able to coordinate which man covers the seam and which takes another receiver; however, realistically there are mistakes made that lead to either the seam route being completely open, or double covered with a shorter route being open.
The most commonly known use of the streak route is in a Hail Mary. This is a play where all four receivers run streak routes. This play is usually used as a last ditch effort and is easily countered by a good prevent defense.
How a defender covers a streak route depends on the defender's position and the coverage. In a zone defense, a corner or safety is the number one key is to make sure they don't turn out of their backpedal too late. The space between a defender and the receiver is a cushion, and when it gets too small, the defender must turn to run with the receiver.
In a man defense, the corner will line up closer to the receiver and must follow them pace for pace. Because there's little question of when to turn, corners covering the receiver in man only have to worry about being faster than the receiver. Regardless of the coverage, once the ball is thrown, it is the defender's job to take away the ball and prevent the catch. This means constantly staying between the receiver and the ball and taking away the receivers inside arm.