It's likely many of them didn't know what they were watching.
"The first thing we have to tell people about our sport is that it's an actual sport," said one of the club members, Ethan Pickett.
Pickett and the rest of the club will have a chance to do just that from 10 a.m. to 7 p.m. Saturday at North Avenue Beach, where club members will conduct the "Chicago Beach Bash" — an event to raise handball awareness. It will feature games, instruction and a few international handball stars, including Germany's Martin Ziemer.
For Americans, there are few if any options for handball, which is definitely not to be confused with the handball in racquetball circles.
Pickett's handball is a fast-paced game played either indoors, with seven players, or on the beach, with four. Picture hockey with its high scoring, line changes on the fly, and goalies —but without sticks and skates — and football with heavy hitting, sans the pads.
Goals are tallied by throwing a ball past a keeper into a net.
"I love the competitiveness, I love the contact, I love the team feel," said Amie Jatta, 29, a three-year member of handball club and an academic advisor for TRIO student support services at Northeastern Illinois University, which coincidentally serves as the club's indoor practice facility.
Pickett, 22, is one of three Americans in the club. He only started playing the game four years ago, when the former guard on Waldorf (Iowa) College's basketball team was introduced to handball by a friend in Minneapolis. Pickett became so advanced in the sport that he has been competing for a professional team in Aarhus, Denmark, in a position literally called a "playmaker."
"The sport just grew on me," said Pickett, who is in the Chicago area for the summer working as an intern in a stock market-related position. "I wish I could have played when I was a little kid."
Jatta is a prototypical member of the club, which has players from Germany, France, Norway, Poland, Russia, Latvia, Lithuania, Bosnia, Serbia, Romania, Denmark, Japan and Morocco.
Jatta was born and raised in Oslo, Norway, where she grew up playing handball. She came to the United States for college and thought she wouldn't be able to find a place where handball was available. But when she arrived in Chicago's Albany Park three years ago, she Googled "handball" and found the club which has been in the city for more than 20 years.
"My first practice, I felt like I was 18 years old again," Jatta said. "Everyone was so welcoming."
On Sunday, the international-friendly flavor was obvious. During one time period, Jatta competed with Jocelyn Goprou, 23, an au pair from France living with a family in the West Loop; Igor Lochert, 41, a construction company owner from Croatia who lives in Logan Square; and Pawel Gryc, 60, an Albany Park dweller who's retired and originally from Poland, where he played and coached professional handball.
"The other players keep me younger," said Gryc, who's the oldest club member and one of its board of director vice presidents.
Like other club members, Gryc wants more Americans involved with the game. The country does have a national team, but it has nowhere near the talent of the world's best squads: Denmark, France, Iceland, Poland and Spain.
Pickett said it will take "baby steps" to showcase handball to his fellow countrymen. Saturday will be one of them.
"It's not something that's going to happen overnight," Pickett said. "But handball is the most American sport that most Americans don't know about."