Generally considered bad form, "Pulling a medford" refers to the act of bringing less beer to a party than you intend to drink, most often a Medford
First Guy at party: "How'd Johnny get so wasted? He only brought four beers!"
Second Guy at Party: "Man, he's had like ten, that dude is always 'Pulling a Medford'."
Johnny: "Dude, you on your way to the fridge? Mind grabbin' be another cold one, brah?"
Medford: <noun> Med-ferd: A pack of beer, usually a six pack, that is two beers short. See also Pulling a Medford
"We asked each guy to bring a six pack to the NCAA Tournament Championship party, but Johnny only showed up with a Medford."