Foreign players and competitive balance in Greek basketball and handball championships

•We evaluate competitive balance in Greek basketball and handball championships.•We utilize 5 indices to measure competitive balance adapted for European Sports.•We examine the effect of the presence and number of foreign players in the league.•We report different findings depending upon the sport and level of competitive balance.•Information for consideration by sports authorities and managers.One of the key issues of team sport championships is competitive balance. One of the dimensions of competitive balance is concerned with the differences in sporting capabilities of teams within a season. The aim of this study is to evaluate competitive balance in Greek basketball and handball championships in relation to the presence and number of foreign players. The examined periods are from 1965–1966 to 2012–2013 (n = 47) for basketball and from 1983–1984 to 2012–2013 (n = 30) for handball. Foreign players appeared in basketball starting from 1988 while in handball from 1999. For each season and sport, two global and three special indices that capture competitive balance in the multileveled championship structure were calculated. Results showed that the number of foreign players per team is dependent on the country's macroeconomic status and in its turn improves the overall competitiveness, as well as competitiveness at the relegation level. In handball foreign players appeared later and in lesser numbers than in basketball. The increase in competitiveness of the national basketball league as a result of the increase in numbers of foreign players across all teams was followed by an upsurge in the quality, performance and achievements of the top teams participating in the European competitions.