The Smash Concept is a popular passing concepts to incorporate into your offense. It is a passing scheme that is designed as a zone-beater, specifically Cover 2 and Cover 4. Coach Jarrett Troxler breaks down the concept in this Glazier Drive clip. He specifically explains the Wide Receivers' routes, the Quarterback read progressions, and the pre-snap reads the Quarterback can make in order to be successful.
In this video, Coach Jarrett Troxler from Massillon Washington HS (OH) outlines the route concept for the WRs and the read responsibilities of the Quarterback.
The Smash Concept is a combination of routes run by two receivers on the same side of the field. The goal is to create a High-Low situation where you are forcing the defender to make a choice. The inside receiver will execute a corner route, and the outside receiver will execute a hitch route or an out route, creating a blanket around the cornerback and forcing him to defend either route. The inside receiver will look to press towards the sideline and the numbers in the soft spot behind the Cornerback and away from the Safety.
While the route concept by the Wide Receivers has a significant factor in the results of the play, it's the Quarterback's crucial responsibility to quickly recognize which route the defender is covering. There are multiple pre-snap reads that can influence the Quarterback's decision. The Cornerbacks' alignment off the ball is a big indicator for some Quarterbacks. If the Cornerback is between 5-7 yards from the Wide Receiver and on his outside shoulder, that is usually an indicator of Cover 2.
Once the Quarterback receives the snap, his job is to confirm the coverage and distance relationship between the Cornerback and Safety and make the proper read. If the Cornerback sinks, he should pass the ball to the #1 Wide Receiver. If the Cornerback attacks the flats, the Quarterback should look to drop the ball in the zone behind the cornerback, but away from the Safety.