Here's the best shot Bill Murray had at the Pebble Beach Pro-Am this past weekend ... The "Caddyshack" actor wasn't playing well at all at the famous Northern California tournament ... so when a fan offered him a mid-round shot of tequila -- he downed it, and the video is hilarious!! You can see in the clip ... Murray was walking up the fairway at one of the holes when a woman leaned over the ropes with a plastic cup full of booze.