I never even try to get ADRs anymore. I have had tremendous luck getting tables for four as a walk-in. You just have to go to the kiosk right when it opens for dinner and they will tell you what time to come back when they think they may have availability. Last week I went to Le Cellier just before lunch ended to see if I could get a walk in for dinner, and they said they had no dinner options available but could take us immediately for lunch. It was perfect - ate a very late, big lunch and didn't even need to have dinner that night.