Pro wrestling is, in a lot of ways, a lot like Major League Baseball. The two entities increasingly find themselves in their own worlds, with their own unofficial codes of conduct, and language/hidden signs that boggle the mind of the uninformed viewer, with the only difference being there's no sign stealing in wrestling. Well, that and most wrestling fans have picked up on what these unofficial signs/signals in wrestling stand for; the dreaded X sign means a wrestler is significantly injured, the squeezing of the hand/foot is to warn a wrestler of a big dive is coming, to let their opponent referee know it's okay, or, in the case of Bret Hart vs. Davey Boy Smith, that it's time to go home.
Then there's another "sign" that really isn't a sign, mainly because, well, it's a clap. Like the other wrestling "signs," wrestlers clapping is pretty easy to spot, not only because it's very easy to see someone clapping their hands, but also because it's hard to watch a wrestling show today that doesn't involve a wrestler clapping their hands right before a crucial point in the match. So what does the signal actually mean in the grand scheme of the wrestling match? Often, it is used to distinguish when it's time for a wrestler to hit one of their trademark moves, as opposed to when the move needs to be reversed, while also giving the opponent a warning that the move is coming, so they can safely prepare for it. The master of this practice is none other than Randy Orton, a revelation that will shock almost no one that has watched the future WWE Hall of Famer extensively over his 20 plus year career.
While Orton didn't always use the clap signal, he began adopting it towards the middle portion of his career, when began using one of his trademark moves, the Snap Powerslam, at a consistent rate. To the naked eye/fan unaware of its significance, the clap before the powerslam is nothing more than a mere tic, something Orton has become so accustomed to doing before the move that it's now become part of the move itself.
This is again where close viewers of Orton can spot the difference. Like any wrestling move, there are times Orton goes for the powerslam, but either has it blocked or reversed by his opponent. What's the difference between that and when Orton hits it? Simple; Orton doesn't clap when his opponent is supposed to reverse the move. As such, the clap has become Orton's way of "calling the match so to speak," with the clap being used to signal to his opponents when they're about to take the powerslam, while the lack of clap signals that it's time for them to block/reverse the move.
In a way, Orton's clap, which has since gone on to be adapted by several other pro wrestlers, is the evolution of a practice AEW's Jake Roberts started in the 80s. Much like Orton claps before his powerslam, Roberts always made a point to slap the back of his opponent before hitting him with his trademark DDT, and always failed to slap the back before his opponent countered the move. All of this was for a similar reason to what Orton does; the slap on the back would signal the DDT was coming, allowing the wrestler to properly prepare himself to take the move, while the lack of it signaled that it was time for a reversal.
