No one who watches NFL games knows what a catch is anymore, or so goes the cool thing to say these days. Here's the unfortunate truth: That includes the referees.

NFL Replay Challenges in 2015 Type Challenges Overturned Success Rate Pass completion 48 26 54.17% Fumble 32 14 43.75% Runner broke plane 30 10 33.33% Incomplete pass 27 11 40.74% First down 20 9 45.00% Down by contact 20 10 50.00% Runner in bounds 8 2 25.00% Loose ball recovery 4 1 25.00% Touchback 3 1 33.33%

Roughly halfway through the 2015 season, there have been more challenges to a pass completion ruling than any other play, according to records the NFL keeps on its statistical website. More than half have been overturned, the highest success rate among the categories with at least two challenges and a big jump from last season (30.56 percent).

The details are in the chart. But in short, the NFL's replay command center -- headed on game days by vice president of officiating Dean Blandino -- has been left to enforce a rule that ostensibly was clarified in the offseason. The new wording, which requires a receiver to become "a runner" in order to demonstrate possession, has led to weekly confusion and too often has required a review.

We've seen replay requested to decide plays involving Cincinnati Bengals tight end Tyler Eifert, Atlanta Falcons tailback Devonta Freeman, Detroit Lions wide receiver Golden Tate and others. The latest: Dallas Cowboys tailback Darren McFadden's first-quarter fumble -- or was it an incomplete pass? -- against the Seattle Seahawks.

On the play, McFadden grabbed a short throw from quarterback Matt Cassel and turned upfield. The ball came loose and was recovered by Seahawks defensive end Cliff Avril.

Referee Carl Cheffers ruled the play a catch and fumble, but all turnovers are reviewed. When you slow down the play, you see that the ball settled into McFadden's right hand and arm. He took one step and lost control as he tried to tuck the ball under his left arm. So even though McFadden wasn't going to the ground, he never qualified as a runner. He did not take multiple steps in possession of the ball, and he was never -- in the eyes of the rulebook, at least -- "capable of avoiding or warding off impending contact of an opponent."

Cheffers announced the reversal, explaining that McFadden did not complete the process of the catch. Rather than a fumble, the play was called an incomplete pass.

Cowboys running back Darren McFadden was involved on a controversial play Sunday. AP Photo/Michael Ainsworth

As I've written before, this ruling makes sense in the deep context of the rulebook and after watching the play frame-by-frame. But no one can see a play so clinically in live action. When more than half of these challenges have been reversed by replay, it's fair to wonder if the NFL has saddled its officials with a rule that is clear on paper but far too difficult to enforce in practice.

The new wording hasn't helped and, if anything, has led to further confusion. The high percentage of call reversals is especially notable, given a standard that requires the play to be "clear and obvious" before any call is overturned. You saw that later in the Seahawks-Cowboys game, when Blandino did not reverse a touchdown by Seahawks tight end Luke Willson because only one of several available replays showed that he was down short of the goal line.

That standard is in place to ensure that games primarily are officiated on the field, not by a remote command center. But the NFL is moving in that direction to enforce its definition of a catch. That's a sub-optimal development, to say the least.

A few quick-hitters from elsewhere in Week 8: