I was there for the 390. It takes some stamina to just watch.:smile:
As for marking the ball positions with chalks.... There are two kinds of asymmetrical purpose-made ball markers available at the table. They prevent errors on replacement. I don't know why they are not being used.
In one of the replacements in the 390 run, the CB was placed on the wrong side of the chalk, thereby making it more than 3" from where it should have been. If John had gone on to beat the 526 in that run, no telling how many asterisks it would have had.
Also, I noticed a foul in another run, with the cue stick bumping a nearby ball on the follow-through. John continued with the run. Then I noticed that the Facebook chat listing of his high runs for each day and the equipment he is using says he is playing cue-ball fouls only. If he does exceed 526, I hope he commits no such non-CB "fouls" in that run.