Vladimir Fedoseev — known across the chess world by his online handle “Bigfish” — is one of the most exciting and uncompromising attackers in the game. Born in Saint Petersburg in 1995, he climbed into the world’s top 25 and has stayed at the elite level ever since, powered by a fearless, complications-first style that has produced wins over just about everyone at the top, Magnus Carlsen included. He reached the semifinals of the 2021 FIDE World Cup and won the silver medal at the 2023 World Rapid Championship, finishing behind only Carlsen. Since 2023 he has represented Slovenia. (All current claims below are as of July 2026.)
Quick facts
- Full name: Vladimir Fedoseev · Born: 16 February 1995, Saint Petersburg, Russia
- Nickname: “Bigfish” · Federation: Slovenia (since 2023; formerly Russia)
- Title: Grandmaster (earned in 2011, at 16)
- Peak rating: 2739 (2025) — a world top-25 level
- Best results: 2021 World Cup semifinalist · 2023 World Rapid silver · 2017 Aeroflot Open winner
- Style: fiercely creative, aggressive, uncompromising — a genuine “master of chaos”
Who is Vladimir Fedoseev?
Fedoseev was born in Saint Petersburg — the same chess-rich city that produced legends from Mikhail Botvinnik to Peter Svidler — on 16 February 1995. A strong junior, he won the under-18 division of the European Youth Championship in 2013 and earned the grandmaster title in 2011 as a 16-year-old. From there he rose steadily through the ranks to become a mainstay of elite chess.
His breakthrough on the international stage came in March 2017, when he won the Aeroflot Open in Moscow — one of the strongest and toughest open tournaments in the world. That same year his rating pushed into the world’s top 25. The defining run of his career so far came at the 2021 FIDE World Cup, where he battled all the way to the semifinals, losing there to Sergey Karjakin and then to Magnus Carlsen in the third-place match — a top-four finish at one of the sport’s most brutal knockout events.
Since the 2022 invasion of Ukraine, Fedoseev stopped representing Russia, saying he had “no will to represent Russia in any competition anymore.” He competed under the FIDE flag before completing his transfer to the Slovenian federation in July 2023, where he immediately became the country’s highest-rated player. He first represented Slovenia at team level at the 2024 Chess Olympiad — where, memorably, he beat world #1 Magnus Carlsen.
What is Fedoseev’s playing style?
If you want a one-word summary of Fedoseev, it’s fearless. He’s a creative, aggressive, uncompromising player who steers toward chaos and complications, trusting his tactical eye to come out on top. He plays for the win, not the draw — even against the very best — and he’s famous for his sky-high “swindle rate,” setting practical traps and refusing to give up even in bad positions. Commentators love him for exactly this reason: a Fedoseev game is rarely boring.
We break this down with examples in Fedoseev’s playing style.
What openings does Vladimir Fedoseev play?
Fedoseev’s openings match his personality: sharp, original, and built to unbalance the game. When he needs a win with Black against 1.e4, he reaches for the razor-sharp Sicilian Najdorf, embracing the sharpest theoretical lines. He’s also happy to surprise opponents with offbeat systems — the combative Dutch Defense or a creative 1.b3 (Nimzo-Larsen Attack) as White — anything that steers the game into fresh territory where he can out-play his opponent.
See his full repertoire in Fedoseev’s openings.
Career highlights
- 2011: earns the grandmaster title at age 16.
- 2013: wins the under-18 European Youth Championship in Budva, Montenegro.
- 2017: wins the Aeroflot Open in Moscow and breaks into the world’s top 25.
- 2021: reaches the semifinals of the FIDE World Cup, finishing among the top four.
- 2023: completes his transfer to the Slovenian federation; wins the silver medal at the World Rapid Championship (9½/13), behind only Carlsen.
- 2024: wins the European Rapid and Chess960 championships, and beats Magnus Carlsen at the Chess Olympiad while playing for Slovenia.
- 2025: reaches a peak rating of 2739 and wins the Superbet Poland Rapid & Blitz leg of the Grand Chess Tour.
The best games
Fedoseev’s highlight reel is packed with wild, uncompromising battles — attacking masterpieces, escape-artist swindles, and scalps of the world’s best. We’ve collected the standouts in Vladimir Fedoseev’s best games.
Fun facts
- His online handle “Bigfish” has become his nickname across the chess world.
- He beat world #1 Magnus Carlsen at the 2024 Chess Olympiad — one of the standout individual results of his career.
- Since 2023 he represents Slovenia, where he is the highest-rated player in the country’s history.
- He’s known for a remarkably high “swindle rate” — an ability to save or even win lost positions by never stopping to set practical problems.
FAQ
Who is Vladimir Fedoseev? He’s a grandmaster, born in Saint Petersburg in 1995, known for his aggressive, creative style and his online nickname “Bigfish.” A world top-25 player, he reached the 2021 World Cup semifinals and won 2023 World Rapid silver, and has represented Slovenia since 2023.
What is Vladimir Fedoseev’s highest rating? His peak classical FIDE rating is 2739, reached in 2025 — a world top-25 level. He first climbed into the top 25 back in 2017.
What country does Fedoseev play for? Slovenia. He completed his transfer from the Russian federation in July 2023 after declining to represent Russia following the 2022 invasion of Ukraine, and is Slovenia’s highest-rated player.
When did Fedoseev become a grandmaster? In 2011, at the age of 16.
Why is he called “Bigfish”? It’s his long-time online username, which fans and commentators adopted as his nickname.
Keep exploring
Dig deeper: his best games · his playing style · his opening repertoire · his rating history · fun facts & records · or browse all chess players.
Written and fact-checked by the Chess Lab Academy Editorial Team · Facts verified against Wikipedia, his FIDE profile, and Chess.com, as of July 2026 · Last verified 2026-07-10 · How we verify content.