An NCAA Division I, II or III player cannot earn money by playing baseball. Doing such would make him a "professional baseball player". The Major League Baseball Amateur Draft is just that… an amateur draft. To be eligible, you need to keep your amateur status. For a baseball player who is looking to get out in front of as many scouts as possible and maybe earn a 6 figure signing bonus … it would be great to show off their talents in an "independent minor league style of play", without getting actually "paid" and ruining their eligibility. CSL's are just like minor league systems… with road games and divisions and playoffs. From the fan's eye there really is no difference between a Collegiate Summer League and independent minor league baseball. They act nearly the same. CSL's allow a player to play a minor league style of baseball in front of scouts and fans just like they would in a minor league environment and still keep their amateur status.