Early career Nijman reached the final of the 2017
WDF World Youth Cup's boys singles event, defeating Ireland's
Keane Barry and Iran's Amirali-Mirzaei Goodarzi on his way. He lost 6–3 in
legs to compatriot
Justin van Tergouw in the final, who he partnered with to win the boys pairs event. In 2018, at the age of 17, he won his first
PDC Development Tour title in the second event of the year by defeating
Bradley Brooks 5–4 in the final. Nijman was able to qualify for the
2019 Czech Darts Open in
Prague as an Associate Member qualifier, but was beaten 6–0 by
Corey Cadby in the first round. He also qualified for the
2019 Gibraltar Darts Trophy, where he won 6–5 against
Darren Webster before losing to
Mensur Suljović. Nijman also won the fourth
Development Tour event in 2020.
Suspension In 2020, the International Betting Integrity Association and the Darts Regulation Authority were alerted to suspicious betting patterns on matches in April and May during the Modus Live League, an online darts tournament series held amid the
COVID-19 pandemic, in which Nijman was involved. He was suspended from attending or participating in events sanctioned by the Darts Regulation Authority in August 2020 after admitting to
match-fixing, which he called a "stupid mistake". A hearing by the Darts Regulation Authority's Disciplinary Committee took place in October, where Nijman's deliberate 4–0 loss to
David Evans on 14 May resulted in him being banned from the sport for five years, with two and a half years of that ban being suspended after he took part in player education and anti-corruption measures. He was also ordered to pay £2,455.74. Nijman accepted the ruling, stating that although he was put under pressure by others to lose the match, he took full responsibility for his actions. His ban ended on 18 February 2023. Nijman featured in an education film released by the Professional Players Federation and the
Professional Darts Players Association in June 2022, where he gave his personal testimony and discussed the repercussions of partaking in match-fixing.
2023 Nijman returned to competitive darts in 2023. In March, he won a national title in the Netherlands at the Rivierenland Open in
Wijchen. He competed in the
2023 PDC Development Tour series, winning three titles in events 6, 12 and 19. He qualified for the
2024 PDC World Darts Championship by placing third on the 2023 Development Tour Order of Merit. His ranking also secured him a two-year
PDC Tour Card for the
2024 and
2025 seasons. Nijman reached the semi-finals at the
2023 PDC World Youth Championship, defeating
Nathan Rafferty and
Owen Bates before losing 6–5 to
Gian van Veen. On 19 December, Nijman made his
World Championship debut, but he lost to
Steve Beaton 3–1 in
sets.
2024 In his full debut year on the
PDC Pro Tour, Nijman qualified for four
European Tours. before losing to
Michael van Gerwen 6–2 in the second round. Nijman topped the
2024 PDC Development Tour series Order of Merit, which qualified him for the
2024 Grand Slam of Darts. He won seven titles over the course of 24 events, including a pair of back-to-back titles: he won events 16 and 17 in July, followed by events 21 and 22 in October. On 1 October, Nijman won his first senior PDC title at
Players Championship 24, defeating
Stephen Bunting 8–5 in the final. Later that month, he competed at the Grand Slam and despite good performances, he finished bottom of his group after losses to Bunting,
Josh Rock and
Gian van Veen.
2025 Nijman entered the
2025 World Championship with high expectations, becoming as high as sixth favourite to win the tournament by
bookmakers due to his good form in 2024. He narrowly defeated South African qualifier
Cameron Carolissen 3–2 in the first round. He was eliminated in the second round following a 3–0 loss to
Joe Cullen. Nijman qualified for the
World Matchplay for the first time and defeated former champion
Nathan Aspinall 10–6 in the first round. He lost 11–5 to
James Wade in the second round. On the
2025 PDC Pro Tour, Nijman reached back-to-back European Tour semi-finals at the
Dutch Darts Championship and the
European Darts Open. He was a two-time winner in
Players Championship events as he earned his second and third PDC ranking titles. He won
Players Championship 30 by defeating
Damon Heta 8–3 in the final, followed by an 8–5 victory over
Luke Woodhouse in the final of
Players Championship 34.
2026 At the
2026 World Championship, Nijman, the 31st seed, defeated
Karel Sedláček 3–0 in the first round. He was eliminated from the tournament following a 3–0 loss to
Gabriel Clemens in the second round. Nijman claimed his fourth PDC ranking title at
Players Championship 2, defeating
Gerwyn Price 8–7 in the final. At the
European Darts Trophy, Nijman reached his first
European Tour final following wins over
Gian van Veen,
Josh Rock and
Niels Zonneveld. In a rematch against Price, he secured his first European Tour title by winning 8–3. In late March, Nijman won
Players Championship 8 with an 8–4 victory over
Joe Cullen. He won a further two Players Championship titles at events
10 and
12 in April, defeating
Scott Waites and
Jermaine Wattimena in the respective finals. ==Personal life==