The Dartmouth student newspaper offers “a three-part series looking at the evolution of beer pong as a social and cultural phenomenon at Dartmouth.”
From the first part:
But the pong players of today, whether or not they realize it, are partaking in a pastime that has come a long way from the original game. Pong consisted of two cups of beer per side from the 1950s until the 1990s, and the last 10 years have seen a proliferation in the amount of beer consumed during one game. The most common pong formations at Dartmouth include “shrub” and “tree,” which consist of seven and 11 cups of beer, respectively. According to common definitions of “binge drinking,” even a single game of pong can cross the line from social to binge drinking.
From the second:
For decades, speed pong dominated — a fast-paced game of table tennis with the added target of beers on the table. Eventually, slam pong came into fashion. In slam pong, one partner lobs the ball to his teammate who slams the ball toward the cup, similar to a set and spike in volleyball. This version, also known as volley pong at the time, was invented around 1979 and came into style in the early 1980s.
“Slam was for the hardcore,” Marriott said. “Regular pong was for women and [fre]’shmen.”