As we approach the 2015 season, there are three baseball players whose cards I will always pull from any box and put aside for sale. Those three players, in alphabetical order are Bryce Harper, Yasiel Puig and Mike Trout. 
To me, they are the most talented trio of under-25 players we have seen 
since the shortstop “holy trinity” of the 1990s–Nomar Garciaparra, Derek Jeter and Alex Rodriguez (and a close fourth just outside those three was Miguel Tejada). However, those names go to show you no matter how great we think the future is for a prospect or a young minor leaguer, there is nothing guaranteed.
My memory goes back to a 1970s card show article in which a dealer stated he’d had enough requests for cards of Jim Rice, Fred Lynn and Dave Parker cards “to drive him up a wall”. During the mid-to-late 1970s, there were few young players more popular than those three. At the time, it looked like all three were going to be Hall of Fame locks. Lynn would have his career year in 1979 and was playing in Boston along with Jim Rice who was coming off two spectacular seasons. 
Meanwhile Dave Parker was saying things such as “When the leaves turn brown, I’ll be wearing the (batting) crown” and wouldn’t you know it, he won the 1977 and 78 NL batting titles.
Who would not have thought these three fine hitters would lead us through the 1980’s and all have Hall of Fame careers clinched by 1985 or so? Instead, while Rice eventually did make the Hall, Lynn and Parker did not.
You may think today’s triad are all going to grow with their greatness and Trout will be the next Mickey Mantle but for all of them we can only hope the future is as great as the present has been. With nothing guaranteed, we as fans are going to be watching with great fascination to see what develops with these players. And while many who have invested in their rookie 
cards hope they are correct, just think if in 1979 you’d purchased the rookie cards of Dave Winfield instead of Parker, George Brett instead of Rice and Robin Yount instead of Lynn, you would have gone against the crowd and done even better in the long term. Hall of Fame careers are carved out in large part after a player turns 30. Consistent, long-term production and general good health elevated all three.
In 1980, it looked like the 1977 rookie card with Jack Clark, Lee Mazzilli and Ruppert Jones had three superstars on it. Instead, you ended with two commons and a minor star in Jack Clark even with his famed 1985 playoff homer.
So far, those who got in early on Trout have seen their confidence pay off in huge numbers. Ken Griffey Jr. lived up to the hype and Trout is probably the most talked about hobby youngster since then…but there’s a long way to go. Common boxes are littered with players who were once considered major stars in the making.
That’s prospecting for you and as long as you can afford to take a chance, it’s all part of the fun. Sometimes you hit big and other times you whiff. As for me, I’ll take my chances and see what the future holds.