Roses clash in 50 overs in 2014
Nottinghamshire and Glamorgan, who faced each other in the YB40 final on Saturday, have been drawn in the same group for next season's 50-over tournament while there will also be Roses and London derby matches in the group stages.
The domestic one-day structure is reverting back to 50 overs from 2014 - to replicate the international format - and there will be two groups of nine with the top four from each qualifying for the quarter-finals.
Lancashire and Yorkshire have been drawn in the same group as have Middlesex and Surrey; teams will play eight group matches, four at home and four away. Netherlands, Scotland and Unicorns, who made up the 21 teams in the 40-over competition, will not be part of the new tournament, for which a sponsor has yet to be named.
Group A Leicestershire, Northamptonshire, Yorkshire, Worcestershire, Derbyshire, Essex, Gloucestershire, Lancashire, Hampshire
Group B Surrey, Somerset, Kent, Sussex, Glamorgan, Durham, Middlesex, Nottinghamshire, Warwickshire