[mrbrandonking]

“... Michelson would run ten or twelve billiards with a touch so delicate that the three balls could always be covered by a hat.”

Michelson was playing billiards on a table without pockets.

I agree that Michelson wasn’t playing 3-cushion because not even Willie Hoppe (best player of that era) had runs 10 or 12 on a daily basis.

Balkline was still popular as an amateur game in the 1920s, so Michelson could have been playing one of the balkline variants rather than straight rail.

Level of difficulty in billiards ...

Straight Rail < Balkline < Cushion Caroms < 3-Cushion