Jeffrey de Zwaan

De Zwaan progressed through to the last 16 of the 2014 World Masters, where he lost to Glen Durrant 3–0. He won a two-year PDC Tour Card in 2015 by defeating Prakash Jiwa 5–1 in the final round.

De Zwaan played at the 2015 German Darts Championship, defeating Devon Petersen 6–2 in the first round before being whitewashed 6–0 by Adrian Lewis in round two. De Zwaan qualified for the 2015 UK Open, reaching the last 16 at the final qualifier. On his debut he lost 5–2 to Benito van de Pas in the second round. He eliminated Steve Brown, Michael Smith, Ken MacNeil and Jelle Klaasen to reach his first PDC quarter-final at Players Championship 4 and lost 6–3 to Lewis. De Zwaan qualified for the European Championship having been the lowest ranked of the seven European Qualifiers but lost 6–3 to world number one Michael van Gerwen in the opening round.

De Zwaan's first year on the PDC tour saw him finish high enough on the Pro Tour Order of Merit to qualify for the 2016 World Championship. His first round match against Michael Smith went to a sudden-death leg. Smith won the bull to throw first and defeated de Zwaan 4–3. He lost 6–5 in the second round of the UK Open to Alex Roy. He reached the last 32 of four Players Championship events and qualified for two European Tours, but was knocked out in the first round of both. De Zwaan reached the final of the 18th Development Tour event but was beaten 4–2 by Corey Cadby.

In the 2018 UK Open, he drew number one seed Michael van Gerwen and won the match 10–8, ultimately ending the World Number 1's unbeaten run in ITV major tournaments since November 2014. He lost 10–8 in the following round to Rileys qualifier Paul Hogan.

In April, de Zwaan won his first PDC ranking title by beating Jonny Clayton 6–5 in the final of Players Championship 10.

At the 2018 World Matchplay, he defeated Michael van Gerwen in the first round 10–6 in legs. This was his second victory over van Gerwen in a major event. This was considered a huge upset due to Michael van Gerwen being the current world number 1 and Jeffrey being the world number 68.

Following Gary Anderson's withdrawal from the 2019 Premier League, de Zwaan was selected as one of nine 'contenders' to replace him. He would play a one-off match against Rob Cross on night nine in Rotterdam.

In May 2019, de Zwaan won his second PDC ranking title by beating Stephen Bunting 8–2.

De Zwaan reached the fourth round of the 2020 PDC World Championship, where he played Peter Wright. Wright led 3–0 in sets and 2–0 in legs before de Zwaan mounted a comeback to level at 3–3 and lead by a break of throw in the deciding set, but Wright eventually won and went on to win the tournament. This was followed by another selection for one of the Premier League nights in Rotterdam, this time under the tag of 'Challenger'.

He lost his professional status at the end of 2022, having dropped outside the top 64 of the PDC Order of Merit. In January 2023 De Zwaan won his Tour card straight back at Q-School, winning the second day. He did so by becoming day-winner on third day of the final stage. At the 2023 UK Open in March, De Zwaan reached the last 32 with wins over Lukas Wenig, Geert Nentjes, James Wilson and Danny Jansen. In the last 32 De Zwaan defeated Gerwyn Price with a 105.20 average. In the last 16, he lost to Rob Cross.

In 2024 De Zwaan continued in his second year with Tour card and signed a multi-year contract with the company Unicorn. In the same time he continued battling with his injured shoulder and was forced to skip several tournaments due to a persistent bursitis problem. He also had to wear dentures due to losing his front teeth. He was only able to qualify for two European Tour events in 2024, being eliminated in the second round at both events. De Zwaan was one of four players to qualify for the 2025 PDC World Darts Championship through the Tour Card Holder qualifier. He lost 3–1 to Florian Hempel in the first round, resulting in him losing his Tour Card.