Pitchers are harder to peg because of the high risk of injury at early ages. After the age of 24, pitchers are less likely to get injured. This doesn’t take injury into account but if a pitcher has a shoulder injury, beware. If he has Tommy John surgery, expect him to be back on the mound in 12 months and another 6 months for his stuff to get back to where it needs to be, as long as they rehab properly and everything worked.
16 years old:
All playing in the U.S. are good prospects
Venezuelan and Dominican Summer Leagues is where the majority play.
17 years old:
Venezuelan and Dominican Summer Leagues is where many play.
Rookie Ball is the likely destination if they are in the U.S.
Short Season if a player is ahead of schedule.
18 years old:
Rookie ball is the likely destination after being drafted out of high school.
Short Season if a player is ahead of schedule out of high school.
All full time players above Short Season are good prospects and are more polished than average.
19 years old:
Rookie ball is if a player is lagging a little behind or a team is very cautious.
Short Season after extended spring training is a likely route.
Low A is the most likely destination, whether to start the year here or join after extended spring training.
High A players doing well are on track to be solid starting pitchers.
AA players doing well are on track to be top of the rotation arms.
AAA players will be stars unless it’s just a few innings.
20 years old:
Rookie ball is not as hard on pitchers at 20 as hitters. Age isn’t quite as important, it’s avoiding injury.
Short Season is a likely destination for college draft picks after they sign and high school draft picks from the previous season after they leave extended spring training.
Low A is a likely destination for players on a slightly slower track.
High A is the most frequent assignment for the better prospects.
AA will be the best prospects, especially if they are not failing.
AAA will be great prospects and the best of these will be future stars.
21 years old:
Rookie ball is not a good destination if they are not college draft picks. If they are anything but, it’s not good.
Short Season is a likely destination for college draft picks after they sign. Prospects coming from here are back of the rotation or bullpen guys at most.
Low A may be for players who are struggling with development. They aren’t guaranteed to fail but it’s not a good sign if they aren’t doing real well here. They typically have control issues.
High A is the most likely destination for players who were college picks the previous year and players who are on a slower track to the majors. They still could be top prospects if doing well enough.
AA is the most frequent assignment for the majority of prospects. Players who do well will have a decent chance of being a starting pitcher.
AAA will have the best prospects and up to 70% could be front end of the rotation guys.
22 years old:
Rookie ball will be nothing more than organizational depth.
Short Season won’t offer a lot, but a handful will make it up to the majors.
Low A pitchers are unlikely to be top prospects but may still be useful bullpen arms.
High A pitchers won’t be frontline guys, but have a decent shot to keep going, especially if there control issues are coming around.
AA is the likely assignment. This is where players frequently find out if they are going to cut it. About a third of the best players become good rotation members. The best of these are #3 starters or better.
AAA pitchers have a tough road. If they succeed here, they have a 50% shot at being a top 3 starter.
23 years old:
Rookie ball ignore.
Short Season ignore.
Low A is for players really struggling to turn tools into skills. Most are likely to wash out.
High A players are very unlikely to succeed. Most are organizational players but there are about 5% of these players that will be big leaguers.
AA is the lesser prospects. They are the guys who have struggled with control but have the arm to be a major leaguer. Some could still be starters but most will be relievers, about 1/3 will be big leaguers.
AAA pitchers are close to a final product. They have a 50% chance of being a solid big leaguer.
24 years old:
Rookie ball ignore
Short season ignore
Low A ignore
High A pitchers are very likely to wash out but a few could still be bullpen arms, not many though.
AA pitchers have taken the longer route but still have a 10% chance of making it, mostly as a reliever or back of the rotation starter.
AAA pitchers could step in and help right now. About 40% will be big leaguers.
25 years old:
Rookie ball ignore.
Short season ignore
Low A ignore.
High A pitchers are really unlikely to succeed, but a few still do. Less than 5% will make it.
AA pitchers are unlikely to be anything more than bullpen arms, but as many as 15% could make it.
AAA pitchers still have potential. Some may be back of the rotation guys, others bullpen arms. 30% of these guys could get a chance in the majors.
26, 27 and 28 years old:
Only pitchers in 3A that have opportunity or are dominating will get a shot, but there are still some who make it.