Ka cika wannan jumla: An haife shi a ƙauyen Stambolovo a kudu maso yammacin Bulgaria, Velichkov ya fara aikinsa na wasanni a aji na shida, lokacin da ya shiga kulob din tseren kankara na gida. Daga baya ya canza zuwa biathlon. Velichkov ya halarci wasannin Olympics na farko a shekarar 1980 kuma ya fara fitowa a gasar zakarun duniya a gasar zakarun duniya a Minsk a shekarar 1982. Ya kuma halarci wasannin Olympics a 1984 da 1988 da kuma Gasar Cin Kofin Duniya a 1983,
1985, 1986, 1987, 1989 da kuma 1990 don Bulgaria. Mafi kyawun sa na mutum a wasannin Olympics ya zo ne a tseren mutum na kilomita 20 a shekarar 1984, ya gama na 13. Mafi kyawunsa, kuma kawai, gamawa ya zo a 1988, wuri na 8. Kyakkyawan sa na mutum a Gasar Cin Kofin Duniya ya zo ne a 1982 a Minsk inda Velichkov ya gama na 5, wani abin da ya kwafa shekaru uku bayan haka a Ruhpolding, duka a cikin tseren tsere. Kyakkyawan sa na karshe a gasar zakarun duniya shi ne na 10 wanda ya zo a 1989 a Feistritz, inda ya fi kyau, kuma kawai, wasan da ya kammala ya zo, a matsayin na 12.