Trail technique is a man coverage technique primarily used by cornerbacks. When playing trail technique, the corner plays a step behind the receiver with his back to the line of scrimmage. This coverage technique gives the corner an advantage against intermediate routes like ins, outs, and curls, as it gives the defender more time to adjust to the receiver’s break. It gives the receiver the advantage in deeper routes as he is already a step ahead of the defender. As a result, trail technique is typically played in coverages like Cover 2 Man because there are defenders deep that can take away the routes that trail technique leaves vulnerable.
On this play, Malcolm Butler is playing trail technique in the slot. On 3rd and 8, Butler is trying to take away any route that comes back to the quarterback that could pick up a first down. Instead, by playing trail tech, he forces the quarterback to attempt a lower percentage throw deeper and into a smaller window. Butler squats at the first down line, turning and attaching to the back hip of the receiver as he reaches the first down marker. This forces the receiver to run the route deeper and puts him in a position where he will have to make a difficult over-the-shoulder catch. He stays with the receiver and keeps the window for the throw small, and the quarterback is unable to hit it.