In 1990, Sergei Makarov of the Calgary Flames became the oldest player, at age 31, to win the Calder. After that season, the rules for awarding the Calder were amended so that players could only be eligible if they were 26 years old or younger by September 15 of their rookie season.To be eligible for the award, a player cannot have played any more than 25 games previously in any single season, nor have played in more than six games in two separate preceding seasons in any major professional league. The latter fact was perhaps most prominent when in 1979–80, first-year phenom Wayne Gretzky was not eligible to win the Calder Trophy despite scoring 137 points (the previous rookie record at the time being 95), because he had played a full season the previous year in the World Hockey Association. The trophy has been won the most times by rookies from the Toronto Maple Leafs, who have won it on nine occasions