Why Bryce Harper isn't a sure thing

Hagerstown, Md., is nestled near the intersection of I-81 and I-70 near the Pennsylvania border, about 75 miles northwest of Baltimore. During the Civil War, its location as a north-south hub made it a major supply center for several campaigns.

In 2011, it will serve as a baseball hub of sorts, as fans and media flock to Municipal Stadium to witness the minor league debut of Bryce Harper, the kid with the powerful swing and swagger to match. If Harper lives up to the expectations, his stay in Hagerstown may be short. If he follows the path of Justin Upton or Alex Rodriguez or Ken Griffey Jr., he won’t be long for the minors and could make his major league debut in September, still a teenager, the first 18-year-old in the big leagues since Rodriguez hit .204 in 17 games with the Mariners in 1994.

Baseball prospects don’t get the publicity of top-rated NFL draftees or NBA prospects, but this is changing. Harper (and Stephen Strasburg before him) has been drooled over like a quarterback with a rifle arm running a 4.5 40 at the combine. Mostly, this is a good thing. It’s exciting to read Keith Law’s annual top 100 list and see how many prospects from your team made it. If you’re an Angels fan, you can dream about Mike Trout’s future. If you’re a Royals fan, you can dream about Mike Moustakas and Eric Hosmer and forget about the impending nightmare of 2011.

On the other hand, it sets fans up for disappointment. The top NFL and NBA prospects receive so much hype and attention, they’re expected to become great. If they flop, the resentment is severe; front-office jobs can be lost; fans turn against the player and team. It gets ugly.

In baseball, we haven’t yet reached that level of expectation. We still have to merely hope. When Buster Posey helps lead the Giants to a World Series title as a rookie, it’s unexpected. When Jason Heyward becomes a star at 20, it’s thrilling. I think this helps form a bond between player and fan that doesn’t quite exist in other sports.

Anyway, we have to be careful here: baseball prospects remain much, much harder to project. Harper may be the best hitting prospect since A-Rod or Griffey, but that doesn’t make him a sure thing. He may be a terrific athlete and possess more raw power than scouts have ever seen on an 18-year-old, but we don’t yet know if he can control the strike zone or how he’ll adjust to quality off-speed pitches.

I will say this, however: I sure want to see him in action. I live in Connecticut and plan on making the drive down to Maryland at some point this spring. He may be starting out in the South Atlantic League, but Bryce Harper is one of the most intriguing players of 2011.

As a final note, let’s play skeptic and explain why Harper isn’t a sure bet to become a superduperstar. Going back to 1990, here are the hitting prospects who ranked in the top five of Baseball America’s top 100 prospects:

No. 1 -- Jason Heyward, Matt Wieters, Delmon Young, Joe Mauer, Mark Teixeira, Josh Hamilton, J.D. Drew, Ben Grieve, Andruw Jones, Alex Rodriguez, Cliff Floyd, Chipper Jones.

No. 2 -- Evan Longoria, Alex Gordon, Justin Upton, B.J. Upton, Rocco Baldelli, Corey Patterson, Pat Burrell, Paul Konerko, Vladimir Guerrero, Ruben Rivera, Andujar Cedeno.

No. 3 -- Mike Stanton, Colby Rasmus, Brandon Wood, Jose Reyes, Hank Blalock, Eric Chavez, Adrian Beltre, Jeffrey Hammonds, Ryan Klesko, John Olerud.

No. 4 -- Jeremy Hermida, Ian Stewart, Sean Burroughs, Vernon Wells, Darin Erstad, Derek Jeter, Alex Gonzalez, Carlos Delgado, Jose Offerman, Juan Gonzalez.

No. 5 -- Stephen Drew, Joel Guzman, Rickie Weeks, Carlos Pena, Nick Johnson, Aramis Ramirez, Travis Lee, Brian Hunter, Tim Salmon, Sandy Alomar Jr.

That’s 53 players. All these guys didn’t become stars, but the success rate is pretty good. Certainly, Delmon Young hasn’t become the batting champion predicted of him, and others like Rocco Baldelli battled injuries, and Ben Grieve suddenly stopped hitting and was out of baseball before turning 30. I would label nine of the players as flops -- 17 percent. Let’s see what happened to those nine.

Alex Gordon – He’s still young enough to put together a career, but he’s never been able to curb his strikeouts at the major league level (362 in 1442 at-bats). Keith Law has said he just hasn’t adjusted to breaking stuff.

Corey Patterson – To be fair, he’s played more than 1,000 games in the majors, but the poor strike-zone judgment he showed in the minors was never rectified, limiting his productivity.

Ruben Rivera – Much-hyped Yankee prospect who hit 31 home runs and stole 48 bases in Class A at age 20, but also struck out 163 times. He never fixed the strikeout issue, whiffing 280 times in two part-time seasons with the Padres.

Andujar Cedeno – Rated the No. 2 prospect in baseball after hitting .240 with 19 home runs in Double-A at age 20. But he also struck out 135 times against just 33 walks. You can predict how that turned out.

Brandon Wood – Has compiled a .169 average in 450 career major league at-bats, with an abysmal 145/13 SO/BB ratio. His big minor-league season came at Rancho Cucamonga, a hitters’ haven, when he hit 43 home runs, but with a poor SO/BB ratio (128/48).

Jeremy Hermida – You can blame a variety of nagging ailments, but outside of 2007 just hasn’t hit as expected. The one player on this list whose strike zone control was supposed to be a strength.

Sean Burroughs – A three-time top-10 prospect, his power never developed.

Joel Guzman – Highly rated following a 2004 season in which he hit 23 home runs between Class A and Double-A. His sin? Take a guess: he had 122 whiffs and just 34 walks that year, and he remains stuck in the minors as a wild swinger.

Brian Hunter – Speedster who put together a five-year career as a starter, but had no power or patience at the plate.

You can see the thread that links most of these guys -- too many strikeouts, not enough walks. Only Hermida and Gordon walked much in the minors. Most of them struck out too much and never did fix the problem.

And that’s the great unknown about Harper. We know of the light-tower home runs and numbers from junior college (.443/.526/.987). He struck out in 16 percent of his plate appearances, which isn’t an alarming rate, especially for a 17-year-old, but high enough to raise at least a little concern. As he heads to Hagerstown, the questions will follow: What if the home runs don’t come right away? What if he gets off to a bad start? Will minor league pitchers throw him strikes? Will he chase bad pitches?

On the other hand: What if he tears up the South Atlantic League? What if he gets promoted and keeps mashing? What if the Nationals are 22 games out in August and attendance is falling and Harper is hitting .321 in Double-A?

If that’s the case … I think we’ll see a lot of Nationals fans suddenly wearing eye black.

Follow David Schoenfield on Twitter at @dschoenfield. Follow the SweetSpot blog at @espn_sweet_spot.