European Tour players have the choice of playing in nearly 50 different events each season. Considered independent contractors by the Tour, the pros can make their own schedule, and they can even be members of multiple tours, including the PGA Tour.
However, European Tour players have to compete in a minimum number of events each season to remain eligible members. This is key for players from Europe because a player must be a European Tour member in good standing to be considered for the European Ryder Cup team. They can't their membership lapse if they wish to ever be a Ryder Cup captain.
European Tour membership requirements
Under European Tour rules, a member must compete in a minimum of four European Tour-sanctioned events that are not the four majors or the World Golf Championships events. In other words, a European Tour member must compete in four tournaments not co-sanctioned by the PGA Tour.
There is also European Tour associate membership, which can be obtained by competing in European Tour Q-school or a single European Tour event. This allows a player to compete for the Race to Dubai bonus pool, which is a measure of controversy, as in 2018 Xander Schauffele won the WGC-HSBC Champions, then became an associate member and finished in the bonus pool money for the Race to Dubai.
Playing on the European Tour requires a commitment, and these standards are reasonable to make sure professionals are supporting the Tour. While the rules have changed over the years, the European Tour has generally been flexible in allowing its higher-ranked players to compete on both tours, patronizing the European Tour when their schedule allows.