During the Supercopa Endesa, the first major tournament of the Spanish basketball season, the sport found a new way to make history in Badalona. On September 19, a challenge that was as spectacular as it was unusual saw 782 participants come together to play the biggest game of knockout basketball ever and, in the process, set a new Guinness World Records mark. The goal was achieved, with the acb, alongside the Badalona City Council and sponsored by energy company Endesa, raising the bar to a record-breaking figure.
Most readers will be familiar with this hugely popular game, played on basketball courts around the world. But what exactly is KO, as it is known in Spain? Internationally known as knockout basketball, it is a fast-paced elimination game in which players must combine accuracy and speed from the free-throw line.
The rules are simple. Players line up, with the first two holding a basketball each. The first player takes a free throw while the second tries to score before them. If the first player makes the shot, they pass the ball to the next player in line. If they miss, they must chase down the rebound and shoot again. The pressure mounts when the player behind manages to score before the player in front, knocking them out of the competition.
The format turns every possession into a race against the clock. There are no defensive schemes or team tactics: shooting accuracy, speed of execution and the ability to handle pressure are what matter. Every shot can mean surviving another round or being eliminated — hence the KO that gives the game its name. As the competition progresses, the line gets shorter and the pace picks up until only one player remains on the court. At its core, it is an individual battle played out in a collective setting, where a free throw can be just as decisive as a game-winning shot at the buzzer.
In Badalona, that simple concept was taken to an extraordinary scale. A total of 782 people took part in the challenge at the Supercopa Endesa Fan Zone, comfortably surpassing the previous world record. The mark had been held by Duke University, which brought together 711 participants on February 17, 2026, at its campus in Durham, North Carolina.
Badalona’s knockout game therefore became the new Guinness World Records mark for the discipline. Duke’s record had itself surpassed the previous benchmark set by the Dallas Mavericks, which stood at 705 participants. The progression highlights how the challenge has continued to grow, reaching a scale befitting a major basketball event.
❤️🥹 “BADALONA, HABÉIS HECHO HISTORIA”
¡Así hemos vivido la mañana de #SupercopaEndesa en la que conseguíamos el @GWR al TORNEO DEL K.O. MÁS GRANDE DEL MUNDO!
7⃣8⃣2⃣ 𝙜𝙧𝙖𝙘𝙞𝙖𝙨 𝙞𝙣𝙛𝙞𝙣𝙞𝙩𝙖𝙨 a los que habéis formado parte de esta BENDITA LOCURA para arrancar el curso. pic.twitter.com/1tYsNAwF9b
— Liga Endesa (@ACBCOM) September 19, 2026
The official certification was carried out by Guinness World Records adjudicator Anouk de Timary, who was present at the Fan Zone to validate the attempt and present the official record plaque to the acb. The tournament was won by Josep Perich, wearing No. 298, who also received a prize consisting of two tickets, including accommodation, for the 2026 Copa del Rey in Valencia.
Badalona has therefore opened the 2026-27 season with a unique showcase of shooting, nerves and quick reflexes. A knockout game on an unprecedented scale, with 782 players sharing the court and pursuing the same goal: to survive shot after shot until becoming the last player standing. The result is now part of basketball history — and, since September 19, part of the Guinness World Records books too.