Simmering tension on the board, unexpected drama off it. Magnus Carlsen’s defence of his world chess title in Dubai began with a 45-move draw against his Russian challenger Ian Nepomniachtchi – and a surprise intervention by the World Anti-Doping Agency. The first game of the 14-match encounter, which has a prize fund of €2m, was eagerly followed by hundreds of thousands of spectators online – another sign of the chess boom that accelerated at the start of the pandemic and again after the Netflix series The Queen’s Gambit. It proved to be an intriguing opening day, which began hours before the first move when Wada warned chess’s governing body, Fide, that it must change Nepomniachtchi’s flag or it would be violating the rules of international sport. Since December 2019, Russia’s flag, anthem and “name in any form” are banned from being shown in any world championship events for two years. It meant that Nepomniachtchi’s flag, which initially said “Chess Federation of Russia”, was deemed to be illegal and had to be hastily changed to the initials CFR. Fide’s president, Arkady Dvorkovich, later confirmed Wada’s intervention to the Guardian, adding: “Yes, we are in contact. We checked several times with them. Maybe at some point our team understood that we could have the full name but then they said ‘no, it should be an abbreviation’. It’s as simple as that.” When the game started Carlsen, the highest-rated chess player in history, and Nepomniachtchi, who is a big underdog here, quickly bashed out their first few moves in a Ruy Lopez. As early as move eight, Carlsen sprang a surprise by playing Na5 which offered a pawn sacrifice. Yet his Russian opponent refused to blink and immediately replied by taking the pawn. This is the way of modern chess: with players using chess engines and supercomputers to discover fresh poisons to inflict on their opponents – and to find antidotes. The two men continued to probe each other cautiously, before finally, on move 13, Nepomniachtchi began to think. The computers showed he had only a slim advantage, despite his extra pawn, with Carlsen’s bishop pair giving him compensation. As a complex game went into the fourth hour, he appeared to be slightly better placed. However, a minor inaccuracy meant the game ended in a repetition. “I should have played Kf4,” admitted Carlsen. “That was a bit poor. I thought that at the end maybe he could try and play but I think realistically it was pretty far from winning.” Such is the game’s growing popularity that the world’s biggest chess site, Chess.com, told the Guardian that the last time the world championship was staged in 2018 it had under half a million daily active users on its site. Now it has more than four million. Another popular site, Lichess.org, said it expected an audience of between 1.5 and 2 million spread across the entire three weeks of the match, across its various content mediums. Meanwhile Chess24 – which is owned by Carlsen – is also investing significantly in the coverage of the world championship this year with a TV studio production, multiple broadcasts for beginners as well as advanced chess players. Those watching certainly saw an intriguing buildup to the match. When the Guardian asked Nepomniachtchi about the ban on his flag, which came about after Wada ruled that Russia had deliberately erased and manipulated doping data stored in a Moscow laboratory to stop its athletes being punished for taking banned drugs, he admitted he was disappointed. “The whole situation is really frustrating,” he said. “The country is technically not banned but the anthem and flag has to be replaced. So this is quite sad. But at the same time my patriotic feeling comes from inside.” The ruling applies to chess world championships because Fide is recognised by the International Olympic Committee as the supreme body responsible for the organisation of the sport. Breaching the ban could have serious consequences for Fide. However Nepomniachtchi, who is ranked fifth in the world, said he was happy enough to start the first game with a draw despite having the advantage of playing with the white pieces. “I was very slightly optimistic during the whole game because this was quite a curious line from black,” he said. “But while he was down a pawn in the endgame it was very hard to win something for white.” Carlsen also seemed satisfied enough, adding: “I wouldn’t say I was ever particularly optimistic in the sense of winning the game. I do feel like I was a little bit shaky at times. [There were] certainly things that I could have done better but overall I think the result was fair enough.” Another 13 games will be played over the next three weeks and such is Carlsen’s popularity that more than a dozen Norwegian journalists are in Dubai to cover the event, which is also being shown on the US TV station NBC.