Kammala jumla mai zuwa: An kirkiro CDs na farko a cikin shekarun 1930 ta ƙungiyoyi daga Burtaniya, waɗanda suka mamaye wasan rawa na kankara don yawancin shekarun farko bayan wasan ya yi nasara a gasar cin kofin duniya.
Gasar cin Kofin Duniya ta 1952. Shahararren CD a cikin rawa kan kankara a hankali ya ragu, har sai an cire shi kuma an maye gurbinsa da SD a cikin 2011, shekarar da ISU ta jefa kuri'a don sake fasalin gasar rawa kan kankara ta hanyar cire rawar tilas da rawa ta asali (OD) kuma maye gurbinsu da gajeren rawa da rawa kyauta (FD).