Late last April, Magnus Carlsen, a calm man of measured words, seemed unusually animated. “Truth be told, I wanted to crush him,” he admitted, after a routine victory in the eponymous Carlsen Invitational. Soon the world champion’s vengeance turned into appreciation of his vanquished opponent: “He’s very, very slippery. Never underestimate him. He is devilishly tricky.”

That slippery, devilishly tricky, can’t-underestimate-opponent Carlsen was alluding to was Alireza Firouzja (surname pronounced as Firoz-jo), a scruffy 16-year-old from Iran with deep eyes and faint moustache, who had twice punctured Carlsen’s aura of invulnerability in the space of a fortnight. First in a marathon 204-game one-minute bullet match in early April and then in an equally engrossing blitz game in the Banter Cup a week later. The second defeat shook the inscrutable Norwegian. He cracked and confided: “It’s really vexing. I’m just constantly doubting myself and it’s all a total mess.”