But you have to be just as skeptical about a player who has a great A ball campaign until they repeat it at the next level.
Many players struggle when they jump levels, one sign of a good player is their ability to adjust.
A few players have the light go on and they blow through the farm system.
Others make steady progress, no one though Hoskins was a top ten player until the spring of 2017 (BA had him #6 for the Phils). But Hoskins had 2500+ PA (college, summer and minor leagues) before he hit the majors.
Some have a great season or two, then flatline at higher levels, that's a concern with Cozens
Pullin looked like he turned the corner last year, then splat this year.
D Brown looked like a world beater, then the world beat him.
2010 at 22 he rips it up at AA/AAA, ranked #48 in MLB 2009, #15 - 2010, #4 - 2011.
It's too easy to get excited about a year or two, or rankings or some scouting report from three years ago.