I’m not normally one to single someone out like this, but here goes:

The Blue Jays’ talent in the upper levels of the minors is really something. They could trade virtually their entire infield on July 31, and then some, and still be better (and cheaper) next year: Donaldson -> Vlad

Solarte -> Bo

Travis -> Biggio

Martin -> Jansen

Pillar -> Alford — Jonah Birenbaum (@birenball) June 22, 2018

Look, I love prospects more than anyone. Over the course of a season, I watch about twice as many MiLB games as I do the Major League version. I like evaluating players, and talking to contacts around the continent about their strengths and weaknesses.

And if there’s one thing I’ve learned from a half-dozen years of writing about them, and a much longer span of observing them in general, it’s this: until they prove themselves at the MLB level, prospects are just that. They are players with plenty of promise, but have yet to realize it.

Minor league performance history is as good a predictor of success as anything, but the jump from AAA to MLB is the biggest one in baseball – maybe even in all of sports. If you have a flaw in your game that your physical talents allowed you to conceal in the minors, you will be quickly and effectively exposed.

This is why teams have three option years on their players. I’m not aware of any recent studies, but this one from 7 years ago found that it took, on average, between two and three seasons for Top Prospects to have their first 2-Win season. It stands to reason that it would take players who are not necessarily near the top of the rankings even longer to attain a 2 WAR year (if they ever do).

The problem, I think, that because many fans’ knowledge of prospects doesn’t extend beyond what they’ve read, or the stats lines they’ve looked up, is that prospects can be enveloped in something of a halo effect. Because they haven’t failed, or maybe because their faults have not been exposed on a prime-time stage, many people think that prospects can come in and take over for an MLB regular.

And more often than not, that’s not the case.

You don’t have to look much farther than the Blue Jays current 25-man roster for proof that prospects still need time to develop once they reach the majors. Josh Donaldson was dealt by the team that drafted him (the Cubs), and after a brief audition with his new team (the Athletics), spent two and a half seasons at AAA before he became an everyday player. J.A Happ, easily the team’s most consistent starter this year, was up and down with the Phillies for three seasons before being dealt to Houston. For every Mike Trout or Kris Bryant who comes up and reaches stardom right away, there are countless players who are sent back to AAA more seasoning.

We know that Bo Bichette lead the minors in hitting last year; what some may not know that he struggled earlier this season (his average bottoming out at .244), mainly because he was chasing too many pitches out of the strike zone. And while his defence appears to be of MLB-quality, he isn’t the best defensive SS in the system – he may not even be #3 at a position where the team is now rich with prospects. This is Bo’s second year of full season ball, and only his third pro campaign. Expecting him to step in and play every day next year is probably unrealistic.

Cavan Biggio has found the Eastern League air and pitching very much to his liking this year, and leads the loop in Home Runs. His defence, at this point, could charitably be described as fringy. He lacks the arm strength and range to play the position in the majors at the moment, which may explain why the team has employed him at several infield spots this season. His bat holds some Rogers Centre promise, but his glove is not ready.

And Lord knows I’m a huge Anthony Alford booster since he took the time to answer a blogger’s questions somewhere over the Pacific, as he was coming home from Australia and a crash course in pitch recognition after giving up his college football commitment several years ago. But his injury history is somewhat concerning, not just because of the frequency, but also because of the time it appears to take him to get back into form after time on the DL. As of this writing, he’s hitting .215/.285/.307 in 45 games with Buffalo.

About the only name (other than Vlad Jr) I might be in agreement with on the above list is Danny Jansen. Even though he’s tailed off a bit, his average dipping just below .300, Jansen is an International League All Star, and the heir apparent to the everyday Catching job once Toronto figures out what to do with Russell Martin and his contract. Still, it’s worth remembering that Jansen has missed some development time due to injury in his minor league career in one of the sport’s lengthier apprenticeships, and he still likely has some learning to do at the MLB level. His initial trial in the bigs may not be successful.

Last fall, Blue Jays President/CEO Mark Shapiro indicated in an interview that the Blue Jays’ brain trust had the tool belts strapped on, and were ready to start a rebuild, but the corporate bosses at Rogers were not comfortable with the drop in attendance and ratings it would likely entail. And the front office knows that progress is not always measured in a straight line, and that their prospects may need several cracks at becoming an MLB regular. Shapiro has also talked about developing waves of prospects who will be ready to go if any of the group ahead of them don’t make the grade. Development takes time, and doesn’t stop once a player is promoted to the 25-man.

The Blue Jays farm system holds as much promise as it has had in some time. To the above list, you could add the recently graduated Ryan Borucki, as well approaching-readiness players like Sean Reid-Foley and TJ Zeuch, and not-far-away prospects like Nate Pearson, Kevin Smith, and Logan Warmoth. With four prospects in Baseball America‘s Top 100, the system is becoming one of the top ones in the game. But that’s not a guarantee of success – it depends on how well those players handle the transition from the minors to the majors. And that’s why teams lacking a key piece will often pay a heavy price in prospects to acquire a player at the trade deadline. A top player with a proven track record has more value – prospects are good, parades are better.