Twitter erupted on Sunday evening over the ending of an NFL game between the New England Patriots and the Pittsburgh Steelers.

It forced people all around the country to ask the same question — What is a catch?

New England ended up winning the game 27-24 after intercepting a pass from Steelers quarterback Ben Roethlisberger in the end zone with only seconds remaining.

But it was the play leading up to that one — one in which Pittsburgh was initially awarded a touchdown — that created the controversy.

Roethlisberger hit wide receiver Jesse James near the goal line for what looked like a pretty obvious touchdown. However, officials ended up ruling that James never caught the ball.

Have a clear look for yourself, courtesy of a Twitter video posted by user @LeadingNFL:

How should that have been ruled?

Officials ended up calling off that apparent touchdown, which would have likely given the Steelers the win.

So, what is a catch?

The NFL catch rule says that a player must complete the process of a catch through the following means, according to the NFL rules site:

  1. secures control of the ball in his hands or arms prior to the ball touching the ground; and
  2. touches the ground inbounds with both feet or with any part of his body other than his hands

James was clearly good on the first two parts, but the question is whether or not he fulfilled the third part of the rule by maintaining the ball.

“If he loses control of the ball, and the ball touches the ground before he regains control, the pass is incomplete,” the rule states. “If he regains control prior to the ball touching the ground, the pass is complete.”

In the video above, it certainly appears as though James maintained control of the ball all the way to the ground, which then jarred it loose (across the goal line, for what it’s worth).

By definition of the second part of this rule, the ground cannot cause a fumble.

And that’s why this play has been so controversial.

Here are a few Twitter reactions: