It's in the ankles, right? I guess even if it's a different part of the body than the inside of one's butt (a sensitive part of the body), makes it plausible that it's also possible for communication (perhaps one-way—towards the plug wearer).

I'm assuming the accomplice would then be watching through some camera feed, right? That makes it at least plausible since there's no need for kegels (to send information the other way).

Wait, what?! That's actually a thing now?!

Not really up to speed with butt-tech. Hahaha! There goes my search history!

that means the person giving you signals is better at chess than you

Def not, that's how cheating is done in online games: you replicate the game and have a computer suggest the next move.

They can use a chess engine to analyze moves more quickly and thoroughly

You can have a whole room of people on the other end of that wireless vibrating buttplug.

Yeah, I mentioned using a simplified notation (still in dots-and-dashes form, though there might be a more efficient way) in a different comment. I actually also mentioned using something like electrical impulses across the small of the back. But then again, that latter one won't really be hidden well (given that this all came about from a challenge of doing chess naked).

There's also the possibility of the accomplice having access to a chess computer (program). But yeah, if the accomplice is better at chess, enough to operate on that level, then why not just have them play indeed?

Oh lol that makes sense. I only relate to the world through IASIP...

"Only"

That's a good point. You wouldn't need to send an entire move. If you simply sent a message indicating which piece is the best to move, the player probably can find the place to move that piece.

This is mostly correct (standard chess notation is slightly more compact than what you described; a typical move looks like "Nf6", meaning kNight to F6. Normally there will only ever be one piece of the appropriate type that can reach any particular square, so only destination coordinates are needed. If it's necessary to say which piece, then you just give origin and destination, but omit the piece, since it's implied by the origin, so moves are typically 3 characters, never more than 4).

As a form of cheating, the use of what are generally called "thumpers" has been around for a long time. In casinos you would have a confederate sitting at an angle where they can see the dealer's hand, who would then signal to you what moves to make. In chess they would be watching the game, constantly plugging every move into a chess program like Stockfish, and then signalling what move the computer chooses. Your opponent is effectively playing the computer, not you.

Typical thumpers are a vibrating band that goes around a leg, or something hidden in the sole of a shoe. All you have to do is sit there and look thoughtful while you decode the message, which is most likely sent using Morse code. Where the sex toys come in is this wild theory concocted by the internet that a really good way to hide a thumper from any kind of frisking would be to use a Bluetooth controlled anal vibrator, since no one is likely to frisk you there. There's no proof that it's ever happened, but now it's a huge meme that chess is basically stuck with forever.

And yes, time is still an issue. Good players can move a lot faster than the time it takes for all that back and forth communication. The strategy, if someone ever suspects they're playing a cheater, is to play defensively and run out the clock.

(edited for clarity)

It's the meme allegation, the real allegation is just cheating without any butt stuff.