Flood
Three-level route overload to one side of the field
Flood is a three-level passing concept that overloads one side of the field with routes at different depths — typically a flat, a curl or out at the intermediate level, and a deep out or corner route. The beauty of Flood is its simplicity: it puts three receivers against two defenders, guaranteeing someone comes open. Bill Walsh popularized the concept within his West Coast offense, and it has become a cornerstone play for trips formations. The concept is especially effective against Cover 3, where three vertical zones leave the flats vulnerable to horizontal stretching.
Route Assignments
Deep corner or out route at 18 yards — the deep level of the three-level stretch.
Out route at 10 yards — the intermediate level sitting behind the flat defender.
Flat route from the backfield — the short level that forces the flat defender to commit.
Dig route providing a backside crosser for when the defense overrotates to the flood side.
Go route clearing out the backside and preventing the safety from rotating to the flood.
Read Progression
Read deep to short on the flood side: look for the corner route first, check the out underneath, then dump to the flat. If the defense overrotates, come back to the dig or check down.
Why It Works
By placing three receivers at three different levels on one side, Flood creates a numerical advantage against zone coverage. The flat defender and deep outside defender must account for three threats with only two bodies, guaranteeing an open window at one of the three levels.