A friend of mine asked me the other day what the prevailing "saber-opinion" was on the Miami Marlins' decision to call up their flame throwing prospect Jose Fernandez at such a young age. I could only tell him that I recall a general sense of confusion as to why the Marlins would call up such a promising prospect when the club is clearly very far from competing for the NL East division title this season.

But as far as concern that this would hurt Fernandez's "development," I don't remember any outcry.

It does seem, however, whenever a prospect is called up this early this voice is is always heard in some manner. I get the impression that some of the concern is with a young player's confidence-- introduce him to failure too early, and he may not recover.

For this reason I think more often than not the narrative gets written retroactively.

Prospect is called up.

Prospect struggles.

Prospect was brought up too early.

This is not to ignore the experts, however. I am sure there are many scouts in the public sector that could speak to 'development' issues much more thoroughly and articulately. But there is no way to prove a premature call up was the cause of a bad career that other wise might have been a good career. In other words, we don't know if a failed prospect with a premature call-up was destined to fail all along.

I imagine it is frustrating for fans to watch one of these kids fall flat on their face amidst all the hype. After all, it is exactly this type of prospect that is supposed to go on and have a storied Hall of Fame type career. And we want to relish that career from the very start. We want to be able to tell our children or our grandchildren we saw one of the best to ever play the game from a very young age. And instead when they fail, it is possible we misdirect our feelings into blame.

Prospects that are awarded their ticket to the show at an early age, especially before the age of 20, typically go on to have some of the best careers. If we look at all careers since 1950, we find that the age 18-21 call-ups ultimately fared the best at the career level according to Fangraphs WAR:

Debut Age Position Players Career WAR avg Career WAR/650 Pitchers Career WAR avg Career WAR/650 16 1 -0.3 -17.7 1 -0.8 -2.6 17 8 10.0 0.4 10 11.6 1.5 18 36 14.5 0.9 29 9.2 0.4 19 96 18.5 1.4 83 13.8 0.3 20 223 16.2 0.8 180 12.4 0.9 21 438 12.0 1.0 423 7.7 0.7 22 651 8.6 0.2 646 6.2 0.5 23 823 5.4 -0.2 792 4.6 0.4 24 849 4.1 -0.3 847 3.0 0.0 25 626 1.9 -1.1 720 2.3 0.0 26 399 1.2 -1.8 486 1.0 -0.3 27 235 1.3 -1.7 287 1.1 -0.2 28 159 0.3 -1.8 154 0.9 -0.1 29 68 0.9 -1.1 72 1.3 0.1 30 50 0.4 -2.6 43 0.5 -0.9 31 21 0.5 -0.4 19 2.2 0.6 32 11 1.4 -1.1 16 1.1 0.6 33 7 0.3 -3.9 7 3.4 -0.5 34 1 -0.6 -4.6 7 1.1 -2.6 35 0 - - 6 0.3 0.2 36 3 -0.1 -6.8 3 2.8 1.2 37 1 -0.2 -4.6 1 -0.2 -1.1 38 1 1.4 1.2 2 4.8 0.3 39 1 -0.1 -5.9 1 -0.8 -5.0 40 0 - - 1 0.0 0.0 41 0 - - 1 1.6 2.2

Of course, this does not mean that if you call up a prospect at 19 he is more likely to succeed. That's ridiculous. What it does mean is that an early call up is typically reserved for the most elite of the elite prospects-- the Hank Aarons, the Mickey Mantles, the Nolan Ryans:

Greatest Careers debuting before age 21 since 1950



# Name Debut Age PA WAR Pos 1 Willie Mays 1951 20 12493 150.1 cf 2 Hank Aaron 1954 20 13940 136.2 rf 3 Greg Maddux 1986 20 20421 114.2 p 4 Mickey Mantle 1951 19 9909 112.2 cf 5 Alex Rodriguez 1994 18 11163 110.9 ss 6 Nolan Ryan 1966 19 22574 106.3 p 7 Rickey Henderson 1979 20 13346 106.1 lf 8 Bert Blyleven 1970 19 20491 105.5 p 9 Frank Robinson 1956 20 11743 104.3 rf 10 Steve Carlton 1965 20 21683 103.1 p

And this is why we get so excited about the especially young call up, and probably also why we are so eager to overreact when they fail.

When we hear a prospect has the goods to get an early call-up, we may draw an immediate association with previous and more notable early call-ups, which may lead to some unrealistic expectations.

Because not all of those early call-ups pan out. And some of them never really pan out. It's those non-pan outs that I would like to interest myself in this morning. At least theoretically. A prospect may be called up for other reasons besides excellent pedigree, I suppose, but we'll just have to deal with that. Here are the worst careers for players who debuted at the age of 20 or younger.

Worst Careers debuting before 21 since 1950



Regardless of how the narrative developed in the media or in the broadcast booth or in the taverns and living rooms, some one saw something in these players that convinced them they were ready to play at the major league level. Some combination of front office personnel, scouting directors, managers made the decision to green light the early call-up, but things just didn't evolve as planned.

Of course, some of these players may not have been prospects, they ay have been filling out a temporary need for the major league club due to injury etc. Dee Brown, for instance, saw just three plate appearances in his age 20 season before his mid-September cup of coffee came to an end.

So let's limit the query to only those players drafted (and signed) in the first round that saw at least 50 plate appearances (or batters faced) before their age 21 season.

Worst first-rounder careers debuting before 21 since 1965

As a 19 year old shortstop in the major leagues, Jack Heidemann had a rough go of it during his first few seasons. A concussion during an outfield collision midway through his age 21 season only exacerbated his struggles, and Heidemann never again saw the full season's worth of playing time he saw as a 20 year old despite remaining in the majors for eight years fro 1969-1977.



Ricky Seilheimer was drafted 19 overall by the Chicago White Sox in 1979 and a year later was promoted to the big leagues. The catcher saw 57 plate appearances before his 69 wRC+ earned him a demotion back to the organizations AA team in Glenn falls, NY the following year. Seilheimer would never again step foot on a major league infield.

Of course we al know Delmon Young's career hasn't been nearly as fruitful as the Tampa Bay franchise had hoped when they selected him first overall in the 2003 draft.Young has been the definition of replacement level in his 3700 plate appearances so far in the major leagues, peaking with a pedestrian 1.6 WAR season in 2010 with the Minnesota Twins. His is probably the most recognizable on the list-- with his career the most recent of the group-- save for only the Toronto Blue Jays' 14 overall pick in the 2006 draft, Travis Snider.



As a 20 year old call-up in 2008 Travis Snider did impress more than a few of us with a 100 wRC+ in 80 plate appearances. His numbers have not been comparable since, even with the change of scenery to Pittsburgh in 2012. As of this morning, Snider has only accumulated 1.6 WAR in over 1200 PAs and counting.

It remains to be seen whether Snider can hang around the major leagues long enough to match Young's playing time, which despite his pedigree is still a rarity beside such a miserable level of production. The leash is probably a bit longer on first rounders-- presumably there is something about these prospects that seduced the front office in the first place. For some players, like Ryan Wagner, injury derails the plan-- while for others like Young and Snider the answer to what went wrong is much more complicated.

Exactly why these players busted while others didn't is a much more involved matter. I generally believe that the prospect would not have panned out regardless of what point he was called up. I'm not saying it's impossible for an early call-up to result in failure and wreak havoc on a player's psyche, I'd just rather not error on the side of wild speculation.



It may be easier to answer this question instead: why were these prospects selected so join the show so early? What was it about their skill sets that so intrigued the scouts that did not translate at the major league level?

. . .

James Gentile writes about baseball at Beyond the Box Score and The Hardball Times. You can follow him on twitter @JDGentile.