Andrew Luck is so good that the third-year Indianapolis Colts quarterback has developed a unique weapon that is invisible to the fans watching his games on television.

The Wall Street Journal interviewed 12 defenders who have recorded a sack or a knockdown of Luck, and each said the Pro Bowler gave them some sort of congratulatory message after the hit.

Philadelphia Eagles defensive back Nolan Carroll told the Journal that it is somewhat unnerving to hear a compliment from a quarterback, because that means he wasn't rattled by the hit.

“You know if you hear a quarterback get mad, you are in his head,” Carroll told the Journal. “With Luck, you thought you hurt the guy, you hear 'good job' and you just say ‘aw, man.'"

The Journal's Kevin Clark writes that Luck will often respond to a bone-shattering hit with a positive response like "great hit" or "good tackle." Sometimes Luck will even throw in the nickname of the defender, as he did when he was taken down by Baltimore Ravens linebacker Terrell Suggs during a recent game.

"Great hit, Sizzle," Luck says at the 40-second mark of this video:

Most quarterbacks either remain silent or complain to the referee about the nature of the hit.

"In all the years I’ve played football I have never heard anything like it,” Washington Redskins linebacker Ryan Kerrigan told Clark. "Nothing even close."

Luck's tactics are so unusual that some players suggested his niceness is strategic; that's he congratulating opponents as a way of getting in their heads. But Luck's father, former NFL quarterback Oliver, says Andrew's sportsmanship is reflective of the way he was raised.

"My wife and I raised all four of our kids with appropriate values, with respect for other people and to be kind and generous and I guess that carried over to the football field," the elder Luck told the Journal.

Of course, Luck isn't the first quarterback to have nice words for his opponents. As evidenced by this game against the Chicago Bears in 2011, Tim Tebow also sung the praises of defenders after they took him down.

The only minor difference between Luck and Tebow is that Luck is "talking the talk" and "walking the walk." Considered by some to be an MVP candidate this season, Luck leads all passers with 4,492 yards through the air and 38 touchdowns. His Colts clinched the AFC South division title Sunday title with a victory over the Houston Texans.

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