Johan Cruyff, who revolutionized the game of soccer, is dead.

According to a statement on his website: “On March 24, 2016, Johan Cruyff died peacefully in Barcelona, surrounded by his family after a hard-fought battle with cancer.”

It wasn’t only that Cruyff—born on April 25, 1947, in Amsterdam—was an ingenious player, inventing moves like the Cruyff turn (above). He was also a master theoretician, a kind of player-coach who in the 1960s and 70s, at his club Ajax and on the Dutch national team, pioneered the concept of total football, in which every player on a team can play every position, resulting in a fluid, attacking, highly complex form of soccer that befuddled opponents.

Total football at times seemed like an aesthete’s dream, more abstract than real, like musical notation that can’t be rendered into sound. It required, at a minimum, 10 extraordinarily versatile players. Its reputation suffered a heavy blow in the 1974 World Cup, when the Dutch team, considered one of the best of all time, lost to the rigid discipline of the West Germans in the final.

But Cruyff brought his theory to Barcelona, first as a player then as a coach, and embedded total football into its DNA. This was why the Barcelona teams of the 1990s were anchored by Dutch players like the de Boer brothers, except in this iteration of total football Dutch tactics were complemented by homegrown Spanish talent (e.g. Luis Enrique) and Brazilian brilliance (Romario, Ronaldo, Rivaldo, the list goes on). 

Cruyff’s influence ultimately resulted in a golden era for Barcelona, for Spanish soccer, and for the sport as a whole. The Spanish World Cup-winning squad of 2010 will go down as one of the best ever. The Lionel Messi era has been nothing less than glorious, a salvation for a sport that until then had increasingly been defined by brute speed and strength, not tactics, teamwork, and creativity. Messi’s Barcelona is total football in full flower, the point at which theory became a reality on the pitch.

It’s but a small example, but recently Messi and Co. attracted attention for executing a cheeky trick in which a penalty kick was used as a pass to set up a rushing attacker. It’s no coincidence that the trick—simple, devastating, and utterly innovative—was made famous by Cruyff. RIP.