Very interestiing topic of discussion. Its true many of the ideas of great players may have never been acutally played on the board & so the world remain oblivious until someone else re-discovers to play them (kind of re-inventing the wheel).
Now since (@HorsesGalore) mentioned about Fischer. I am posting two games with somewhat rare opening choices by him.
Excuse me for not putting any annotation- as Fischer's game are way beyond my ability to analyse/comment.
Bobby Fischer had the reputation of playing the same openings.
When other Chess players were only concerned about new opening theory Bobby Fischer went in the other direction he studied yellowed and worn copies of Wilhelm Steinitz's International Chess Magazine and Fischer paid close attention to the German Hanbuch Des Schachspiels by Von Bilguer and Von der Lasa a very large book the equiviliant of Chess Informant and Modern Chess Openings for the 19th century.
I've got the book right here it's a treasure trove of long forgotten opening lines no longer in any opening books and it has many traps tricks and secrets within it's pages he must have learned a great deal from it.
Bobby Fischer had the reputation of playing the same openings. He coined the expression 1 pawn to king 4 is "best by test" and for awhile stuck with that all the time.
When he tried something different in the openings or a "new" variation for him, it was news -- became all the rage for others to try. Often it happened, once Bobby played for him a "new" variation, what were once well respected opening variations were then thought to be suspect or no good ! For instance, when he started playing the White side of the Ruy Lopez Exchange Variation, people started thinking that's a great way to gain the advantage for White.
Do any of you think there may be many more opening ideas / twists Fischer had, but died with him -- as he seldom played chess after winning the world title in 1972 ?