Super GMs often catch cheaters by creating a stale board in the late mid-game and watch opponents make pointless moves many times in a row. It becomes pretty obvious at that moment.

There's a "no news" zone between a discovery and proliferation. In 1997, deep blue become superhuman.. proving the point. The average consumer engine was still like average tournament player with really weird moves. It took another decade before superhuman engines became widely available to normal people.

That decade gap is where we often mispredict the future. Once a point is proven, we expect instant impact. Reality takes time.

It took 15-20 years after superhuman chess engines were invented before they really impacted chess. Cheating is one impact, but novelty is another one. "Computer moves" are learned by GMs and played in world class tournaments. Contributing novelties is a mark of influence in chess. Even computer strategies are starting to appear in human tournaments.

The difference between a super GM and stockfish is that a super GM will play moves the "feel natural" to a human given the current position on the board. A chess engine won't care about what is natural and will maximize the position 15-20 positions down the line. For this reason, they will make sometimes a weird move given the current position that will result in an advantage a lot of moves downstream.

One of the main reasons that Petrosian "got caught" was other GMs (see Hikaru's YouTube video on this) pointing out how unnatural some of his moves felt to them and considering the speed at which he supposedly calculated them.

> EDIT: Heh, deep blue’s famous match happened in 1997. I guess this really is possible. It’s weird growing up with the idea that “every chess engine can beat humans every time”; I wonder when that became true.

There is an interesting section in Hofstaeder's Gödel, Escher, Bach from 1979 where he speculates that, despite the rapid progress of technology, computers might never be able to play chess at a human level!