Kammala jumla mai zuwa: FIDE ta ba Nielsen lambar yabo ta International Master a 1991 da ta Grandmaster a 1994. Ya lashe gasar zakarun Danish sau biyar: a 1996, 1999, 2001, 2003, da 2008. Ya buga wa Denmark wasa a wasannin Chess Olympiads bakwai, sau uku a saman jirgi, tare da sakamako na gaba ɗaya na 60.1% (+ 24−10 = 35). Ya lashe lambar zinare ta mutum a kan kwamitin na uku a
Moscow a shekara ta 1994.