Getty Images/Jim Rogash
Under NFL rules, an offense has to have five players on the field who are ineligible to catch a pass. These five players are usually offensive lineman and they usually are stacked in the middle of the field to protect the quarterback.
In the AFC divisional playoff against the Baltimore Ravens, the Patriots ran three straight plays where they stacked four ineligible receivers in the middle of the field, with a fifth eligible receiver next to them to look like a blocker. They put their fifth ineligible player further along the line of scrimmage to make him look like a receiver.
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When the Patriots snapped the ball, the receiver disguised as a tackle ran out for a pass, while the ineligible receiver stayed on the line of scrimmage, as ineligible receivers are not allowed to run out past the line of scrimmage.
The formation and play totally fooled the Ravens, and the Patriots marched down the field with three straight completions for first downs. In this play, Michael Hoomanawanui ran unguarded because the Ravens thought he was ineligible:
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After the game, the Ravens were upset about the plays, with John Harbaugh saying:
"We wanted an opportunity to be able to ID who the eligible players were. What [the Patriots] were doing was they announce the ineligible player and then Tom [Brady] would take them to the line right away and snap the ball before we had a chance to figure out who was lined up where. That was the deception part of it. It was clearly deception."
He added that the referees didn't know what was going on, either.
In preparation for the Super Bowl, referees had hand signals to help the Seahawks know when the Patriots were using this formation.
The Ravens, obviously, were happy about the new rule:
NFL owners have passed the rule proposal banning the use of ineligible receivers like the Patriots did in the AFC divisional playoffs.
- Baltimore Ravens (@Ravens) March 25, 2015