Pedzisa mutsara unotevera: Akaita kuoneka gumi nemaviri paIAAF World Cross Country Championships kubva muna 1977 kusvika muna 1995. Mumwe nomumwe, kuita kwake kwakauya pa
1983 IAAF World Cross Country Championships, uko akaiswa wechinomwe zvachose. Clarke akanga ari katatu sirivha medalist pamakwikwi (1982, 1987, 1989) uye akahwinawo chikwata chendarira muna 1992, kugoverana kukudzwa naMike McLeod, Hugh Jones, Julian Goater, Steve Kenyon, Karl Harrison, Carl Thackery, Kevin Forster, Steve Binns, Tim Hutchings, Gary Staines, Richard Nerurkar, uye Eamonn Martin, pakati pevamwe.