Going through my memories of various important moments that I can think of ("The Drive", "We want the ball...", "Beastquake", etc.), the vast majority of them were L to R. The only big ones I could think of going the other way were the Tyree catch and the final kick to finish "the comeback". Diags, your mention of some other R to L seems true, now that I reflect on them.
No big bold theory here, was curious if people can cleanly remember the directions or if the direction is "lost" in the memory (my wife says she doesn't really remember what direction the drives are going in but she remembers key pieces of the drives).
Just thought it would be an interesting quiz.
"The past is a foreign country: they do things differently there."---LP Hartley