Y gwahaniaeth rhwng diwygiadau o "Rygbi'r undeb"

:Rhif 9 Mewnwr <!--- (scrum-half)--->

:Rhif 10 Maswr <!--- (fly-half)--->

:Rhif 12 a 13 Canolwr (x 2) <!--- (center)--->

:Rhif 11 a 14 Asgellwr (x 2) <!--- (wings) --->

:Rhif 15 Cefnwr <!--- (full back)--->