LOGANVILLE, Ga. -- The most unfair play in football is not some gadget drawn up in a dusty coaching office or an outlawed scheme for which no defense exists.
It's Robert Nkemdiche on a toss left, running with a full head of steam at a high school cornerback protected only by his pads and helmet. And it happened for the first time on the practice field down a path through the woods outside Grayson High School last week.
For those in attendance on the sideline and spread across the field, it made for a scary sight: Nkemdiche, a 6-foot-5, 270-pound defensive tackle who moonlights as a running back, took the pitch in stride. Showing his 40-yard dash speed of 4.6 seconds, he barreled toward the secondary -- in particular one young defender, outweighed by 100 pounds.
For a moment, Nkemdiche (pronounced kim-DEECH-ee) appeared ready to hit the cornerback. Observers prepared to cover their eyes. Alas, the smaller player jumped back as Nkemdiche ran past, head still down.
This is only practice. Some day, coach Mickey Conn will call the play in a game. And a cornerback might actually find himself in front of the 17-year-old runaway train, to this point used mostly as a running back between the tackles.
"I don't know how you'd get him down," Conn said after practice on that hot, Georgia afternoon.
Asked if he takes pity on the defensive backs charged to tackle him, Nkemdiche said yes.
"I feel bad for them to a certain extent," he said. "But when it's game time and I get the ball, I'm not thinking about it. I just play the way I was taught to play. I feel if they put you on a field, either you do it or you don't. That's how I look at things."
Easy for him to say. A rare combination of size, strength and speed, Nkemdiche collected 18 sacks last season.
Though a junior, he fits among the top high school players in the nation and rates as a headliner on the newly released ESPNU Watch List.
Grayson, ranked No. 16 in the ESPNHS Fab 50 and a semifinalist two of the past four years in Georgia's largest classification, uses him primarily on defense. Offense is fun, Nkemdiche said, but he understands his play in the trenches has drawn the attention of recruiters nationally.
Nkemdiche knows plenty about Ole Miss, where his brother Denzel, a freshman safety, attends, and Alabama, at which Conn played from 1992 and 1994. Nkemdiche visited the Tuscaloosa, Ala., campus last spring.
"I like Alabama," he said. "Good coaches, good school and good everything."
But he said he wants to further examine both schools and take visits also to Florida and LSU.
Others may squeeze into the race, too. It's too early to consider when he'll settle on a college.
"When that day comes around," Nkemdiche said, "everybody will know."
The son of Sunday Nkemdiche, an Atlanta-area physician, and Beverly Nkemdiche, a representative in the congressional assembly of the Nigerian state of Anambra, Robert emerged as an elite prospect after his performance in April at the Nike Football Training Camp in Athens, Ga.
At an event stocked with top 2012 prospects, Nkemdiche stood out as perhaps the best.
"Age, to me, doesn't mean a lot," he said.
Vadal Alexander, a 6-6, 310-pound offensive tackle from Buford, Ga., with offers from every top Southeastern Conference program in addition to USC, Notre Dame, Texas and others, marveled at the kid.
"Just a specimen," Alexander said. "He could be a once-in-a-decade player."
Alexander likened Nkemdiche to Chicago Bears star Julius Peppers, a North Carolina native with 91 career sacks. Nkemdiche likes the association. He studies film of Peppers and tries models his work habits after the three-time NFL All Pro.
At Grayson, he plays all over the defensive front, moving often to best avoid double-teams. Nkemdiche said he figures to bulk up to 290 or 295 pounds in college and play tackle. Perhaps instead of Peppers, he ought to watch Ndamukong Suh, who, incidentally, tried a little fullback in college at Nebraska.
Conn, the only coach in Grayson's 12-year history, isn't ready for the big-name comparisons.
"There's no doubt he's a talent," Conn said, "but there's a lot of things that can be refined."
Conn first saw Nkemdiche in film delivered to the coach of an eighth-grade game. He was impressed, so Conn went to watch Nkemdiche play. He returned a kickoff for a touchdown.
"It was unbelievable," Conn said. "Great talent."
Nkemdiche played on the Grayson varsity squad as a freshman. He's been on the fast track since.
Now, it seems, Conn must invent ways to challenge Nkemdiche -- like run him on a toss play out of the offensive backfield.
And when he gets the call in a game?
"I'm going to run full speed and see what I can do," Nkemdiche said.
If he gets matched in open space with a little cornerback, remember to cover your eyes.
Mitch Sherman is a senior writer for ESPN.com. He can be reached at firstname.lastname@example.org.
Follow Mitch Sherman on Twitter: @mitchsherman