The relationship between date of birth and expertise in various sports is well established, and known as the relative age effect (RAE). However, new results in e.g. Canadian Hockey (Gibbs et al., 2012) and British cricket and rugby (McCarthy & Collins, 2014; McCarthy, Collins, & Court, 2015) have found a reversal of RAE among selected talents where the youngest athletes are more likely to remain selected than their older peers. As such, RAE may therefore depend on the level of seniority and competition of athletes. The purpose of this study was therefore to analyse RAE in the progression from youth to senior national level in a sample of successful Danish male national teams. The sample included 244 players from the Danish under-19, under-21 and senior national levels. These players have been part of succesful teams, winning 18 medals at 24 youth European and World championship and 8 medals during 12 years at senior level. The results showed a significant RAE on both youth national levels. However, RAE was less marked from the under-19 to under-21 and further so to the senior national level. Results show that at national youth level talent selection favours the relatively older players, of whom a larger proportion fail to progress to the senior level compared to their younger peers. RAE should therefore be seen as a dynamic mechanism that interacts with not only the selection of athletes but also their development.