Dating back to the Burt Emanuel non-reception in the 1999 NFC Championship game, the NFL has tweaked the rule. For all those attempts, the league has gained no clarity into what constitutes a completed catch. Calvin Johnson's overturned TD in 2010, the Dez Bryant's wiped away play in the 2014 playoffs, Sunday's ruling and myriad other instances have left most players, coaches and fans scratching their heads in frustration. The only consistency with the rule is the degree to which it confounds spectators and athletes alike.