Chess myths

"Chess960 is a variant"
"Position 518 has perfect harmony"

Myth: Perfect play corresponds to roughly 4,200 Elo.

Concrete number may vary, mostly it appears to between 500 and 1,000 points higher than the currently best playing entity.

Perfect play has nothing to do with Elo. Elo is a measure of how many practical problems do you create to other, non-perfect, opponents. You can play perfectly in a mathematical sense and still always end in a draw against Stockfish dev and weaker engines, yielding Elo below the Elo of SF dev itself, which doesn't make the moves to hold the true value of position, but rather tries to get the most comfortable position for practical play.

@Wolfram_EP Elo is nothing but the rating compared to other people you play

you either win and gain Elo or lose and lose Elo

Unfortunately, there are also draws which can also cause you to lose Elo.

Elo is an estimation of the outcome based on prior encounters. So where does the quality or the game itself come into play? You can even calculate Elo tables for soccer or table-tennis which actually is done.

Some myths are easy to refute, others are are true indeed. Like practicing by means of blitz games which all masters actually do. Scanning a large area of training issues within a short time is a good thing.