The best way to define the West Coast offense may be to start with what it isn't.
The traditional passing game, which NFL teams ran for years, is based on deep drops, quarterbacks bouncing and waiting for receivers to come open, one-on-one matchups and throwing the ball downfield.
In contrast, the West Coast offense as it originated with Bill Walsh is any play or set of plays that tie the quarterback's feet to the receiver's route so there is a sense of timing.
The offense cannot be taught or run based solely on a playbook. If a coach has no history in the West Coast and wants to teach it based on a playbook, he wouldn't get it. Timing and choreography, not plays, are what make the West Coast offense.
My definition might include a number of teams that aren't generally thought of as West Coast offense teams. In fact, most of the league uses some of the West Coast philosophy and perhaps even the Walsh tree of plays. For the most part, the system and the plays are intersecting, but they don't need to be. The quick slant is considered a staple West Coast play -- dropping three steps, planting and throwing on time and in rhythm with the receiver. But there are tons of ways to design West Coast plays, even if they didn't originate with Walsh.
Two weeks ago I visited the Patriots and met with quarterback Tom Brady. When I asked him about his drops and his reads, he said everything is about finding space, zone routes, man-zone reads, short drops and timing. Brady's footwork tells him when to throw the ball. So, while offensive coordinator Charlie Weis has no West Coast history or ties to Walsh and the 49ers system in his coaching background, the Patriots essentially are running the West Coast offense.
Meanwhile, based on how Kurt Warner and the other Rams quarterbacks throw the ball, Mike Martz does not run a West Coast offense in St. Louis. He uses a more traditional passing game in which the routes are not tied to the quarterback's feet.
Bucs coach Jon Gruden, who worked under Mike Holmgren in Green Bay, will say, "We're not running the West Coast offense. I'm running my offense." Well, that's fine, Jon. And sure, he and other coaches may feel they don't run the West Coast, because they don't run Walsh's plays from 1980.
But I disagree. Although Gruden may run different plays and have different names for certain aspects of his offense, his plays are designed with the quarterback's footwork in mind. And that is the West Coast offense.