keypusher: <ounos: I don't think they would have substantially better chances using another opening.>
I do! Dus Chotmirsky, Rabinovich and Gotthilf all did better (at least in the opening) with different variations of the Ruy. But that's not so important. Lasker made no effort against Gotthilf, not much of one against Rabinovich, and Dus was one of his famous escapes.
Here's what caught my attention in the Yates, Bohatirchuk and Romanovsky games: Black is pretty much busted by move 20. That shouldn't happen in any opening, but especially not in a closed Ruy Lopez.
In each game, Lasker was able to open the queenside with a4-a4, exploit the underdefended d5 and g4 squares, and the exposed bishop on f6.
More than most defenses, the closed Ruy Lopez is an affair of fashion; sometimes, just as with clothes, the fashions get really ugly.