The Calder Trophy is an annual award presented by the National Hockey League (NHL) to the league's most outstanding rookie player. Established in 1936, the trophy is named after Frank Calder, the first president of the NHL. The winner is determined by a vote of the Professional Hockey Writers' Association at the end of the regular season. To be eligible for the Calder Trophy, a player must be a rookie, meaning they have played fewer than 25 games in any previous NHL season. The award recognizes not only individual talent but also the potential for future success in the league.