Alireza Firouzja, the Iran-born Frenchman, is a rekindled talent after the 21-year-old triumphed unbeaten in this week’s $350,000 Sinquefield Cup at St Louis.

Firouzja totalled 6/9, half a point ahead of the US champion and world No 3, Fabiano Caruana. The world champion, Ding Liren, drew his first six games and lost two of his final three and finished next to last on 3.5/9.

The prestigious event, named after the chess benefactor Rex Sinquefield, is one of the game’s three elite super-tournaments, along with Tata Steel Wijk aan Zee in the Netherlands and Norway Chess at Stavanger.

Three years ago, Firouzja seemed destined for a quick journey to the top. He was the youngest ever to reach a 2800 rating, easily qualified for the 2022 Candidates, and was effectively named as Magnus Carlsen’s heir apparent.

Then came failures in the 2022 and 2024 Candidates, a quarrel with the Wijk aan Zee organisers, an episode of all-night one-minute ­bullet games in the middle of a major ­tournament, a decision to work on an alternative career in fashion design, and an alarming drop in the world rankings from second to 16th. Some believed that he had lost the dedication and commitment to succeed at the ­highest level.

In the past few months Firouzja has made significant changes to his lifestyle. He appears more relaxed with interviewers and opponents, has cut back substantially on blitz and bullet games, and has arrived at the board with well-prepared openings. His world ranking has jumped back up to No 5.

In retrospect, Firouzja’s marathon win against Caruana in round one was pivotal to his victory. The loser pressed for many moves, but missed a drawing chance by 80 Rd5! Caruana got compensation in a later round when he defeated his old rival Ian Nepomniachtchi, whose Dragon Sicilian blunder 18 g5? allowed the winning counter 18…Nxe4!

The tournament winner had a let-off when Gukesh Dommaraju, after a strategically impressive game, failed to find 47 Kg2! followed by Rxa6 when White should win with four pawns for the exchange.

Firouzja’s most emphatic victory was against the world champion, where he deliberately kept the position ­complex and tense until Ding ­collapsed in time pressure. Firouzja has now beaten Ding four times in their last five meetings, while in the fifth, at Stavanger, he won the ­Armageddon replay after a classical draw.

Ding seemed to be playing better at St Louis than in his previous 2024 events, but he ended tied for eighth out of 10, without winning a single game. He had a minus score for the fifth classical tournament in a row, a negative record for any world champion.

Ding’s challenger, India’s 18-year-old Gukesh, drew every game, but still showed himself a master of defence and ready for long, stamina testing, encounters. Betting odds for their world title match at Singapore in November-December before St Louis were 5-8 on Gukesh and 11-5 against Ding.

Fide’s annual World Rapid and Blitz championships will be staged on Wall Street, New York, on 26-31 December. This is a major development for the popular event, whose last five renewals have all been played in Asia or in Eastern Europe.

Magnus Carlsen, Norway’s world No 1, holds the rapid and blitz titles, and is ranked world No 1 in both. Carlsen will defend his crowns against a challenge led by the Nos 2 and 3 Hikaru Nakamura and Caruana, both of the United States. China’s world champion, Ju Wenjun, heads the entry for the women’s events.

Traditionally the World Rapid/Blitz has been played over five days, three for 13 rounds of rapid and two for 21 rounds of blitz. Rapid is 15 minutes per player per game, plus a 10 seconds per move increment. Blitz is three minutes per game, plus a two seconds per move increment. Fast chess formats are among the most exciting in the sport, demanding quick and intuitive decisions plus strong and resilient nerves. They are a test both of skill and of mental endurance, making them a favourite for players and spectators.

This year there will be a free day in the middle, devoted to Chess Davos, a conference exploring the links between chess and finance. The new schedule has evoked widespread criticism,both from players concerned about scarce and costly accommodation, and from chess media due to the overlap of the final blitz rounds and New Year celebrations.

Britain’s problem solvers struck gold in Jurmala, Latvia, at the end of July. The team of John Nunn, Jonathan Mestel and David Hodge won the World Solving Championship in the chess equivalent of a photo finish. They were equal on points scored with the holders, Poland, but solved in a shorter time.

Related: Boy, 15, becomes youngest British chess grandmaster

It was Britain’s first success in this competition since 2007. Since then, Poland have won 13 times, and they were again the heavy favourites. Nunn and Mestel are grandmasters, while Hodge qualified for the team by winning the annual Winton British Solving Championship, whose open entry starter problem was published in this column in June. The key move which solves the starter problem is given below.

Nunn’s personal achievement was impressive. The eminent chess author, who has written classics on all aspects of the game from openings to endings, now holds six world or European championships simultaneously.

Nunn is already the reigning world and European over-65 senior champion, and won golds three and four with England at the European and world senior team championships. Now he has his fifth and sixth from the individual senior and team world solving titles in Jurmala.

Joseph Blackburne, nicknamed “the Black Death”, and one of England’s all-time greatest players, died a century ago on 1 September 1924. At his peak in the 1880s he was world No 3 behind only Wilhelm Steinitz and Johannes Zukertort. He was a great showman in exhibitions against chess clubs, and is remembered for his quip after drinking a simul opponent’s glass of whisky: “He left it en prise so I took it en passant.”

Blackburne’s life and career is chronicled and assessed in an excellent biography by Tim Harding.

3935: 1 Nf6! Kxf6 (if Qxf3? 2 Nxe8+) 2 Be5++! Kxe5 3 Qxe4+ (3 Qxf7! Rd8 4 f4+! Qxf4 5 Re1+ also wins, but is harder to calculate) Kxe4 4 Re1+ Kf6 5 Rxe8 and White wins one of Black’s bishops with a decisive rook v knight endgame. Solving starter problem: 1 fxe4.