In conferences held at the Oberwolfach Institute, participants usually dine together in a room witg tables of different sizes, and each participant has an assigned seat. Gerhard Ringel asked whether there exists a seating arrangement for an odd number $$v$$ of people and…

Abstract Single-elimination tournaments are the standard paradigm both for the main tennis professional associations. Schedules are generated by allocating first seeded and then unseeded players with seeds prevented from encountering each other early in the competition. B…