Ruy Defense

Wow. I am quite surprised by Lasker. But it's true that he played tons of different stuff.

I also only looked at free online databases. Botvinnik apparently played it at least 5 times, mainly in the Absolute URSS championship, against very strong opposition.

It's interesting that we associate the Ruy Exchange variation with Lasker although he rarely used it.  He used it in several important games spread throughout his career.

I associate lasker as black mainly with the steinitz variation, but i haven't really checked so i might be wrong. 

Reb, I believe Korchnoi was a avid user of the Open for a while.  At least it seemed he was one of the last ones to use it regularly. 

His favorite defense to the Spanish was the Berlin (4...Nf6), some  transposed into variations of the Steinitz when White played d3.

Larsen also played the Open Ruy as black and even wrote a book on it I believe. 

Thanks for the information. The fact is that in My System Niemzowitsh gives some Lasker games in the steinitz variation, so I erroneously guessed that it was his favourite line.