The secret’s out. For half a season, Atlanta Hawks fans kept word of the Josh Smith Show to themselves, with his sky walking feats softening the blow of his team’s nightly beatings. But Smith is no longer basketball’s best-kept secret: His already-legendary exploits in the dunk contest in Denver took care of that.

Now Smith is proving to the basketball world that he’s more than just a dunker. The 6-foot-9 southpaw confirmed that Tuesday night in his first game as Josh Smith, NBA Dunk Champion, going for a career-high 19 points and 10 rebounds in a loss to Sacramento. Needless to say, his performance is another feather in the cap of those who think high schoolers can jump to the NBA right away and make a difference.

While his bionic leaping ability makes him a threat around the rim, Smith’s scoring totals aren’t what make him stand out. His offense is hindered by a shaky outside shot and having to play out of position at shooting guard on a rebuilding Hawks team.

No, what stands out about Smith are his spectacular rejections. He is averaging nearly two blocked shots a game, which is pretty impressive considering he plays only 24 minutes a night. It’s fun to watch because the reaction of opposing players is always the same – who was that? Smith clinched one of Atlanta’s rare wins this year when he raced out to block an Aaron McKie 3-pointer at the buzzer – and he was about 10 feet away from McKie at the time.

No night stood out more than his 10-block effort against Dallas on December 18. Yes, 10. Three different times in that game, the Mavs’ 7-foot star, Dirk Nowitzki, dribbled past Smith and went to the rim for a dunk. Smith sent back all three of them. The Hawks lost, of course, but Smith’s impressive performance served notice (to the few who watched, at least) that he had arrived.

The Hawks’ lack of success and Smith’s low scoring average are making him a nonfactor in this year’s Rookie of the Year race, but when all is said and done, he may be the best player from this season’s draft. To see why, let’s take a look at my Player Efficiency Rating, which measures each player’s statistical production on a per-minute basis. While Emeka Okafor of Charlotte and, lately, Ben Gordon of Chicago have gotten most of the Rookie of the Year buzz, Smith has outplayed both.

How can a guy with such modest averages – 8.2 points and 5.3 rebounds per game – rank at the top of the list, when players like Okafor and Howard have much more impressive averages? Two reasons stand out.

First, despite his low scoring average, Smith is a fairly efficient scorer. He hits 47.9% from the field and, because he gets to the line fairly often, averages 1.06 points per shot attempt. That separates him from the next guy on the list, Okafor, who averages just 0.94. Additionally, because Smith has played fewer minutes, his per-game averages exaggerate his offensive shortcomings. He averages 13.2 points per 40 minutes, which isn’t great, but is better than Howard’s 13.1 and not far from Okafor’s 16.6.

Of course, the other reason Smith rates so high is all those blocked shots. Smith averages 3.1 blocks per 40 minutes, which ties him for fourth in the league with Tim Duncan and Eddie Griffin (the league leader, Theo Ratliff, swats 3.6 shots per 40 minutes). Howard and Okafor, by contrast, weigh in at a tame 2.0 and 1.6 blocks per 40, respectively.

In other words, Smith already is challenging to be the best shot-blocker in the league – even though he has no idea what he’s doing on defense yet in terms of positioning and helping from the weak side. Howard and Okafor are miles behind.

Smith’s sensational debut is part of a larger trend as well. This year’s draft featured eight high schoolers in the first 19 picks, and six of them already have made major contributions. Of the six best rookies this year, at least three are high schoolers – Smith, Howard, and Boston’s Al Jefferson, who has been outstanding in limited minutes off the Celtics’ bench.

Several of them weren’t even high picks. Atlanta took Smith 17th overall – after passing him over at no. 6 to take the far less productive Josh Childress. Jefferson went 15th to Boston, behind such luminaries as Rafael Araujo and Kris Humphries. Sebastian Telfair of the Blazers and J.R. Smith of the Hornets also went outside the top 10, yet each has made major contributions.

Enjoy the high-school brigade while it lasts, however, because this is the last of the Mohicans. Most scouts consider this year’s high-school crop a total dud, with no probable lottery picks and perhaps only three players worthy of a first round selection.

After that, we hit the Minimum Age Era. The new collective bargaining agreement between the NBA and its players, which the two sides still are negotiating, is almost certain to include a requirement that players be at least 20 years old before playing in the NBA. Thus, all the Josh Smiths and Al Jeffersons of the world will either have to toil for free in college for two years before tasting the NBA’s riches or go overseas to get a paycheck right away.

So while my memory of All-Star weekend is that the Josh Smith Show finally went prime time, it’s likely to go down in history as the end of an era rather than the beginning of one. Because even as teenage players – including, of course, Le-Bron James – are showing that they can compete at the pro level right away, this is likely the last we’ll see of their kind for a very long time.