Sebastian Bialecki

Białecki started playing darts in 2015, at the age of 12.^[] Białecki's first significant achievements were winning the Polish Junior Championship twice in 2017 and 2018. In 2019, he took part in international tournaments for the first time. At the beginning of 2020, he took part in PDC Q-School in order to obtain a PDC Tour Card, but was unsuccessful. He also took part in PDC Development Tour tournaments in Hildesheim, Germany, where he reached the Last 32 three times, and reached the semi-finals once, losing the match for the final with Ryan Meikle. In September 2020, he took part in the 2020 PDC World Youth Championship, advancing from group stage to the second round, where he again lost to Meikle, this time 0–6.

In 2021, he took part in Q-School again, but was again unsuccessful. Good results on the Development Tour allowed Białecki to play in the 2021 UK Open. He was the first player in history to be born after the first edition of this tournament.^[] In the first round, he faced Jim McEwan, achieved a nine-dart finish, and won the match 6–2. In the following matches of the tournament, he defeated Jitse Van der Wal (who also hit a nine-dart finish against him) and Derk Telnekes. He was eliminated in the fourth round, losing to Mensur Suljović 6–10.

In September 2021, he won his first PDC Challenge Tour title in Niedernhausen, beating Kevin Doets 5–4 in the final. Two months later, in November 2021, he won his first PDC Development Tour tournament beating Geert Nentjes 5–4 in the final. In November, he also took part in the 2021 PDC World Youth Championship, but was eliminated in the group stage after going winless.

Much like last year, Białecki qualified for the 2022 UK Open as a Development Tour qualifier. In this tournament, he achieved his best PDC result to date, beating Matt Campbell, Joe Murnan, Keegan Brown, Ritchie Edhouse, Ian White and Ryan Searle to reach the quarter-finals. He was eliminated by William O'Connor 9–10, despite having a match dart for a 150 checkout on double 15.

In April 2022, he took part in Denmark Open, his first senior WDF tournament and won the title, beating Ben Hazel, Andy Baetens, Dennis Nilsson, Shaun McDonald along the way before defeating Darren Johnson 6–1 in the final. This win guaranteed him qualification for the 2023 WDF World Darts Championship. In the same month, he took part in East Europe Qualifiers for the PDC European Tour and qualified for three tournaments.

In his European Tour debut at the 2022 Czech Darts Open, he lost 4–6 to Martijn Kleermaker in the first round. He was eliminated in first round of the 2022 Dutch Darts Championship, where he lost 1–6 to Jelle Klaasen. On 4 June 2022, he won his second PDC Development Tour in Hildesheim, beating Keane Barry 5–3 in the final.

Białecki took part in the 2022 PDC World Cup of Darts, representing Poland with Krzysztof Ratajski. In their first match, Poland struggled against Danny Baggish and Jules van Dongen of the USA, but Poland won the match in a last leg decider. In the second round, Poland faced Belgium, with Białecki playing Kim Huybrechts in a singles match to start the contest. He lost the match 2–4, with Ratajski's loss to Dimitri van den Bergh sealing Poland's elimination.

At the beginning of July, he played at 2022 European Darts Matchplay. He won his first match on the European Tour with a 6–4 victory against Mervyn King. He lost 5–6 to Stephen Bunting in the second round after Białecki missed a match dart on double 20. At the end of the month, he took part in the soft-tip Polish Darts Championship. In the men's singles he beat Łukasz Wacławski in the final, winning his first senior Polish Darts Championship title and qualified for the second soft-tip EDF European Darts Championship in his career.

At the end of September 2022, he was selected by the national federation to participate in the 2022 WDF Europe Cup. On the second day of the tournament, he advanced to the finals of the pairs competition where he played together with Dariusz Marciniak. They were defeated by England's Joshua Richardson and Scott Williams 2–6.

He participated in the East Europe Qualifier for the 2023 PDC World Darts Championship. On his way to the final, he defeated Michele Turetta, Alexander Mašek and Rusty-Jake Rodriguez. In the final, he faced Christian Gödl and won 7–4.

At the 2023 PDC World Championship, he lost 3–2 to Jim Williams in the first round.

In 2024, Białecki participated in the 2024 PDC Development Tour series. He finished 5th on the Order of Merit, but finished 2nd in the Development Tour's Tour card race which means he received a 2-year PDC Tour Card for the 2025 & 2026 seasons.