Štancl reached the final of the Speedway World Championship on nine occasions between 1971 and 1984, finishing a career best 9th in 1982 in Los Angeles.

He won the Czechoslovakian National Championship twelve times, appeared in the World Team Cup finals on seven occasions and in the Speedway World Pairs Championship finals seven times.

Štancl won the famed Golden Helmet of Pardubice in 1974, 1976, 1978, 1981 and 1982

Son George also rides.

World Final Appearances

Individual World Championship

1971 - Gothenburg, Ullevi - 13th - 3pts
1976 - Chorzów, Silesian Stadium - 10th - 6pts
1977 - Gothenburg, Ullevi - 14th - 3pts
1978 - London, Wembley Stadium - 15th - 2pts
1980 - Gothenburg, Ullevi - 13th - 5pts
1981 - London, Wembley Stadium - 16th - 3pts
1982 - Los Angeles Memorial Coliseum - 9th - 7pts
1983 - Norden, Motodrom Halbemond - 16th - 1pt
1984 - Gothenburg, Ullevi - 16th - 1pt

World Pairs Championship

1970 - Malmö, Malmö Stadion (with Václav Verner) - 5th - 11pts (6)
1972 - Borås (with Jan Holub I) - 6th - 12pts (7)
1973 - Borås (with Petr Ondrašík) - 6th - 11pts (9)
1977 - Manchester, Hyde Road (with Jan Verner) - 4th - 17pts (11)
1978 - Chorzów, Silesian Stadium (with Jan Verner) - 4th - 18pts (9)
1982 - Sydney, Liverpool City Raceway (with Aleš Dryml, Sr.) - 7th - 8pts (5)
1984 - Lonigo, Pista Speedway (with Aleš Dryml, Sr.) - 6th - 10pts (5)

World Team Cup

1970 - London, Wembley Stadium (with Zdenek Majstr / Václav Verner / Miroslav Verner / Jan Holub) - 4th - 3pts (0)
1977 - Wrocław, Olympic Stadium (with Václav Verner / Jan Verner / Aleš Dryml, Sr) - 3rd - 23pts (8)
1978 - Landshut, Ellermühle Stadium (with Václav Verner / Jan Verner / Aleš Dryml, Sr) - 4th - 16+2pts (7+2)
1979 - London, White City Stadium - 3rd - 19pts (6)
1980 - Wrocław, Olympic Stadium - 4th - 12pts (4)
1982 - London, White City Stadium - 4th - 17pts (4)
1983 - Vojens, Speedway Center - 4th - 3pts (2)