http://www.csnne.com/new-england-patriots/harbaugh-explains-origin-legal-version-pats-trick
In part:
In last year’s AFC Divisional Playoff, the Ravens – after pre-play announcements were made as to which players were lining up as eligible – gummed up their coverage. They did so even
AFTER referee Bill Vinovich told the Ravens prior to one play not to cover Shane Vereen. It wasn’t illegal. It was inventive.
Harbaugh complained that it was “clearly deception,” called it unprecedented (it wasn’t) and said the officials let him down. He did so in his clipped, condescending, smarter-than-thou, tougher-than-thou tone which is meant to convey unassailable authority but really just announces that he’s an interesting mashup of whiner/bully/tattletale/teacher’s pet.
Having gotten his way with the competition committee,
Harbaugh ran a “legal” variation of what the Patriots did. It should be pointed out that what the Patriots ran wasn’t “illegal” until Harbaugh and the Ravens complained.
On Sunday, the Ravens put a player with an ineligible number – Marshal Yanda – in the slot outside the tackle box. He was – like Vereen in January – ineligible to go out for a pass. And the Raiders – like the Ravens in January – covered an ineligible guy anyway and got beat for a significant play.
It is a distinction without a difference. Both plays are designed to make the defense figure out who should and shouldn’t be regarded as a downfield threat. In fact, the Ravens – taking advantage of possible confusion caused by the rules change they affected – were more shady in pulling that play given their involvement in getting the rule changed and acting as if they’d been “victimized.”
On Wednesday, Harbaugh explained to ESPN’s Jamison Hensley how the play came to land in the Ravens’ playbook.
"I don't remember when it went into the playbook originally," Harbaugh said. "I thought it was really a well-organized play. Conceptually, it's something we've been talking about for a while. But any way you can move the ball and any way you can find a way to get a guy open -- you really strive to do that and it's hard to do that -- and we were able to do that on that play."
Just trying to move the ball and get a guy open. What’s the big deal?