ku dhameystir weedha soo socota: Dagaalkii Labaad ee Adduunka kadib, Dennis Morton Horne wuxuu ka fariistay ciidanka isagoo ahaa kabtan wuxuuna wax ka bartay Jaamacadda Oxford, halkaas oo uu si dhab ah ugu qabsaday ciyaaraha chess-ka. 1948 tartanka caalamiga ah ee Plymouth, wuxuu ku guuleystay horyaalkii hore ee adduunka ee Max Euwe. Sanadkii 1949 wuxuu ku guuleystay kaalinta 2aad ee tartanka British Chess Championship. Wuxuu ahaa ciyaaryahan shaashad ah oo qaab-dhismeedkiisu aad u xeel dheer yahay, isagoo inta badan adeegsanaya furitaanka shaashadda sida King's Gambit. Dennis Morton Horne ayaa xulka Ingiriiska u matalay ciyaaraha Chess Olympiad ee
1952, oo uu ku guuleystay billad lacag ah oo shaqsi ah. Sanadkii 1954, wuxuu wali ka qeyb qaatay Shirweynihii Caalamiga ahaa ee Chess-ka ee Hastings, kaas oo, inkasta oo uu ka sarreeyo Friðrik Ólafsson, haddana wali kaalinta ugu dambeysa. Sanadihii danbe, Dennis Morton Hornespent waqti yar ayuu ku qaatay ciyaarista chess-ka, inta badan wuxuu ku mashquulsanaa Bridge-ka qandaraaska.