What would Ruy Lopez de Segura rating be?

I absolutely love chess history. But there are far better uses of time than reading the old books if your goal is chess improvement. You will have to unlearn as much as you learn.

Several decades ago, I studied the games of the McConnell-LaBourdonnais match. There were some interesting openings, and some memorable tactics. But one of the most startling aspects of the games was that the players clearly favored Ns over Bs and were willing to make schoolboy trades to get the Ns!

Modern chess theory begins Morphy.

I think most of you are underestimating Ruy Lopez's playing strength as well as that of other players of that time. While its true the best players had an unsophisticated understanding of openings, positional play and endings, I believe their tactical abilities were at least master strength. To them that was the essense of the game...mating attacks and combinations. There are examples of sophisticated chess-like compositions going back to at least 1000 AD. I imagine Lopez would rate well on chess.com's tactical exercises. So, I would guess Roy Lopez rating at 2000- 2200.

He recommended to make the rival sitting in front of a window so he was bothered by the sunlight, ¡coño!

Apparently, it needs explanation. Ruy Lopez famously advised setting up the board so that the glare of the sun was in the opponent's eyes.