'For most, if not all, of these high school or college players, they must also traverse multiple levels (Rookie, Low A, High A, AA, AAA) of the minor league “farm” system. This is often where the MLB dream stalls out, with roughly 10-15% of minor leaguers making it to the Big Leagues.'
https://joeeisenmann.substack.com/p/what-is-the-road-to-major-league
When they make the 40 or 26 after Spring Training, there is good reason for optimism, any thing before that is actually some loathing players that made it because some one's favorite Boy/s is/are not there.