Prospecting is far from an exact science. The biggest flaw that I have seen in my years of doing this is hype. I was just messing around with a spreadsheet I'm trying to finalize for my rankings this year and decided to look at a prospect and similar prospects from previous years. Jameson Taillon was my first victim. Taillon has had a good season. Not a great season but good. He hasn't dominated like I expected him too out of high school and I don't know that he will. I think he will be a solid middle of the rotation arm with the chance of being better than that on occasion. I have evidence why I believe that.
Some of the names that pop up when looking at similar players are interesting to me. Jason Bere, Joel Hanrahan, Jason Grilli, Sean Burnett, Ricky Bones, Dan Serafini, Pat Hentgen, Shane Loux, Ryan Kibler(who?), Gavin Floyd, JD Durbin, Kyle Drabek, Adam Eaton, Tony Armas, Pedro Astacio, Brett Myers, Ricky Nolasco, Dicky Gonzalez, Derek Lowe, Andy Pettite, Kyle Lohse, Chuck Lofgren, Dave Borkowski, and the list goes on..
What this tells me is that he is likely to have a successful big league career. What this doesn't tell me is how successful and when he will impact. There are a lot of possible outcomes. There is a chance he washes out and becomes another Ryan Kibler, but he is likely going to make it to the majors and be a solid mid rotation guy with a few seasons in which he is better than that. Will that disappoint most people? Probably. My point is that is shouldn't. That will still likely be a top 5 to 10 career WAR performance from the players drafted the same year as he was. He should not be a disappointment but a success because that is the best that was available at the time. Considering he was just 18 and likely won't be an impact player until he is 22 or 23, maybe later, that is a hell of a job by the team who developed him. It's a win but unless he is an ACE, people will be disappointed.
I'll tell you what, there aren't any ACE's in the minors right now. None. Will one develop from the crop of minor leaguers, maybe. There are a handful that have the right ingredients, but none have shown they have what it takes to lead a rotation.
Tijuan Walker, Matt Wisler, Noah Syndergaard, Lucas Sims, Nick Kingham, AJ Cole, Rob Ray, Clayton Blackburn and Yordano Ventura haven't logged big innings and could improve command. Archie Bradley walks too many but he's close. Henry Owens, Tyler Glasnow, Jesse Biddle and Lance McCullers have a long way to go on command but the tools are there. Rafael Montero could even be in the mix. This is all from looking at stat lines and comps. My guess, one of these is an ace. Take your pick but even if ALL the tools are there, don't expect the ceiling. Most of these guys will end up filling a spot in an MLB rotation and will save some team from a long, overpriced contract to fill the role that they end up filling.
Ok, rant over..