Quoted from Whysnow:but to clarify slightly...
the vast majority are in use for tournament play all day Thursday and Friday.
Most are available on Saturday (only a smaller subset are reserved for play in finals of each division)
All are available on Sunday.
This is disappointing and probably should be noted on the website somewhere. I booked a hotel and bought tickets for just the Thursday and Friday and wanted to play the free play games listed on the website.
There are over 400 pinball machines listed under the games section of the website and it says they will all be set to free play. A note about the vast majority being unavailable for free play Thursday and Friday would have been nice.