and FC Dallas respectively, now only control one franchise. League executives Don Garber has been the commissioner of Major League Soccer since 1999, serving as the league's chief executive. The league's first commissioner was Doug Logan, who served in the role from 1995 to 1999. Mark Abbott, a former MLS business partner, has served as the league's president and Deputy Commissioner since 2006. Player acquisition and salaries The average salary for MLS players is $373,094, lower than the average salaries in England's second-tier EFL Championship ($420,000 in 2015), the Netherlands' Eredivisie ($445,000), or Mexico's Liga MX ($418,000 in 2015). The league's minimum player salary increased in 2017 to $65,000 for most players, and roster players #25–30 saw their minimum salary increased to $53,000. MLS salaries are limited by a salary cap, which MLS has had in place since the league's inception in 1996. The purpose of the salary cap is to prevent the team's owners from unsustainable spending on player salaries and to prevent a competitive imbalance among teams. The salary cap survived a legal challenge by the players in the Fraser v. Major League Soccer lawsuit. The 2017 salary cap increased to $3.845 million per team. Each team is allowed up to 30 players on its first team roster. All 30 players are eligible for selection to each 18-player game-day squad during the regular season and playoffs. Teams may augment their squads by signing players from other leagues. MLS has two transfer windows—the primary pre-season transfer window lasts three months from mid February until mid May, and the secondary mid season transfer window runs one month from early July to early August. When an MLS club sells one of its players overseas, the club and the league split the transfer revenues, with the club retaining from 33% to 75% depending on the player's status and tenure. MLS teams have a limited number of international roster slots that they can use to sign non-domestic players. However, MLS teams often obtain green cards for their non-domestic players in order to qualify them for domestic status and thus free up international roster slots. In 2015, 49% of MLS players were born outside of the U.S. and Canada, with players from 58 countries represented. MLS has a set of pool goalkeepers who are signed to a contract with the league and are loaned to teams during emergencies in which they are missing a