Finally. After spending 15 minutes squeezing your way through the cacophonous, slimy mass of drunken flesh occupying the rest of the dark, low-ceilinged dive, you’ve finally made it to the bar.

There are 30 other customers “next” in line and a lone bartender. Is there any effective way to lobby for your drink?

The bartender-customer interaction is one without instructions. There’s no velvet rope, no “take a number” routine that brings order to the chaos. It’s one person behind the bar with nearly unlimited power, determining which thirsty patron gets to order next seemingly on whim alone. Or is it? I spoke to a bunch of bartenders to better understand the dynamic.