Let me start by saying that I cannot answer this question. The Cubs have way more information than I do and I won't criticize them if at some point they choose to promote him. I won't criticize them if they leave him in High A.
I want to talk about something specifically. It's a comment I often hear and believe I read yesterday (may have been something Myles wrote, but I think it was a quote from someone else).
"He's got nothing else to learn at that level."
Obviously whenever someone says this, and I know I've said it a dozen times, it's obviously an overstatement. Every player has something to learn at every level. At no point is a player at a point where he has nothing ot learn from the level he's currently at.
Mostly though, this is actually something we can look up. A player with nothing else to learn will excel at all aspects of the game. This is simple enough to verify.
There's another comment that I know I've also said a dozen times that is not entirely true.
"The player will have to learn the skill or skills he's currently lacking in at a higher level."
It's going to be a lot easier for Javier Baez to learn some plate discipline at the easier level than it will be at the higher level. Theo and Jed have said they have some benchmarks for players to clear before they promote them and this is why. Obviously Javier Baez can hit for a lot of power, but he's shown little ability in getting on base via walks. To his credit. he's always had a high HBP rate. He's been hit by a pitch 20 times in his career and only walked 25 times. To some extent, Baez is making up for his low walk rate. At the same time, his walk rate can still be much better.
Promoting someone because he'll have to learn how to walk at the tougher level seems like a good way to ensure the player doesn't develop the skill. If a player hit all non-fastball pitches exceptionally well, but couldn't hit the fastball for shit, he might actually have pretty good numbers. For awhile.
At some point they'll just pound him with nothing but fastballs and those numbers will go down. Learning to hit a fastball is a necessary skill and it's best learned at lower levels. If you keep promoting a guy who can't hit a fastball because he has to learn how to do that at the next level, he's probably never going to learn.
If learning to be more selective is a skill the Cubs want Javier Baez to learn, they should probably keep him in Daytona. The Chicago Cubs aren't any good, won't be good next year and probably not the year after. There's no hurry. It's important that the development of these guys is done right and not just to get a player to the big leagues.
What the answer to this question is, I do not know.