Pseudo-Boolean optimisation for RobinX sports timetabling

Abstract We report on the development of Reprobate, a tool for solving sports timetabling problems in subset RobinX format. Our is based around monolithic translation instance into pseudo-Boolean (PB) optimisation problem; this can be solved using existing solvers. Once has found feasible solution, it improve second encoding that alters only home/away pattern games. entered our International Timetabling Competition 2021. While was effective many instances, struggled to cope with schedules involving large break constraints. However, among instances which could initially find combination use portfolio solvers, range variations and aforementioned local improvement process yielded an average reduction solution cost 23%.