ORLANDO, Fla. — For every moment of triumph and glory in college football, there might be a chop, an eye gouge, an after-the-whistle gang tackle, a leg twist, a yank of the dreads or, in the spirit of Dallas Cowboys safety Roy Williams, a horse-collar tackle.

Dirty plays have become as much a reality in the game as pep rallies, but the NCAA aims to prevent potential injuries at all costs by tightening its grip on what's considered a penalty.

A horse-collar grab is now good for 15 yards as of last week, thanks largely to the trend popularized by Williams that forced the hand of the NFL rules committee in 2005. Variations of facemask grabbing or twisting are also 15 yards.

As players tote the line between playing physical and down-right cheap, some say the always-changing rules of the game shouldn't affect an assumed code of ethics.

Even if your style of play is perceived as cheap.

"You can play really physical like I do, but you should never have any intent to hurt anybody," USF senior offensive lineman Ryan Schmidt said.

Perhaps it wouldn't be the game we love without compromising body contortions, abrasive reactions and offensive and defensive lineman bickering over who's the dirtiest.

That's typical stuff. What might not be as typical is a defensive player giving props to the NCAA for making it harder to tackle.

UCF defensive tackle Torrell Troup doesn't mind.

"I actually think all the rule changes are a good idea," Troup said. "I know a lot of guys like to use the horse tackle, but I don't mind the change. You never want to hurt another player and there are a lot of other ways to tackle someone."

Safety aside, the difficulty of tackling a player without penalty is becoming "a little out of hand" these days, Florida defensive line coach Dan McCarney said.

Gators strong safety Ahmad Black said playing efficient defense is taking more and more improvisation.

"You find a way to get him on the ground," Black said. "People think an aggressive player is a dirty player — when it's football, it's football."

Here are five of the "dirtiest" plays you'll see in college football, with the criterion based on the likelihood to injury.

HORSE COLLAR

By definition: When a player grabs either the inside back collar or the side of the shoulder pads or jersey and immediately pulls the runner down. This does not apply to a runner who is inside the tackle box or to a quarterback who is in the pocket.

Penalty: Personal foul, 15 yards

Ruleworthy because of: Its element of surprise and the potential leg or knee injuries to the ball carrier as his legs gets swept from under him. "That's straight-up intent to injure somebody," Schmidt said. "The guy's running full speed and there's nowhere for his legs to go but under him."

Famous incident: The rule was basically implemented for one man: Roy Williams. In 2005, the Dallas Cowboys safety forced the hand of the NFL rules committee for his reputation of the one-arm grab that belongs in the WWE ring. Then-Philadelphia Eagles receiver Terrell Owens sat out part of the 2004 season with a fractured fibula after Williams got ahold of him.

CHOP BLOCK

By definition: Any high-low combination block by any two players against an opponent other than the runner, anywhere on the field, any time in the game and with or without a delay between the hits.

Penalty: Personal foul, 15 yards

Ruleworthy because: A helmet to the knee is just asking for a sprain or a torn Anterior Cruciate Ligament.

Famous incident: Last season, Auburn offensive lineman Chaz Ramsey could have cost LSU defensive tackle Glenn Dorsey millions in the NFL draft with his nasty chop-block work. Ramsey went lower than Flo Rida into the knees of the Tigers' beast while his teammate was blocking his upper body. It was so obvious that even Auburn Coach Tommy Tuberville issued an apology. Dorsey left the game with a right knee sprain but returned in time to lead the Tigers to the national championship.

THE PILEUP

By definition: When an opposing player grabs, pulls, pokes, gouges or attempts to take away another player's ability to have children inside the pile surrounding a gang tackle or fumble.

Penalty: Depends on the foul, but unsportsmanlike conduct is worth 15 yards.

Ruleworthy because: It's just a dirty way of doing things.

Famous incident: Florida fans will never forget about Florida State nose tackle Darnell Dockett, who allegedly grabbed UF running back Earnest Graham's knee and twisted it with the intent to hurt. Graham suffered a sprained knee, prompting former Gators coach Steve Spurrier to go as far as suggesting that FSU coaches instructed this sort of behavior. Bowden said Spurrier's comments were "sad." A former Florida Today correspondent reported that Dockett bragged to teammates during a postgame locker-room scene about his hit on Graham.

CLOTHESLINE OR KARATE CHOP

By definition: Something that wouldn't make Mr. Miyagi from The Karate Kid proud.

Penalty: Unnecessary roughness or striking an opponent with a fist, both 15 yards.

Ruleworthy because: You might as well spend your Saturdays at a dojo.

Famous incident: This might seem like an obscure tactic, but it's a way defensive lineman fake a random arm flare while coming down on a quarterback. Take LSU defensive end Tyson Jackson, who waited until Kentucky quarterback Andre Woodson was practically on his knees before coming down on his neck with a Cobra Kai chop last year. Kentucky got even in the worst way: It defeated LSU 43-37.

FACEMASK

By definition:Grabby, grabby . . . keep those fingers away from the helmet.

Penalty: Facemask, 15 yards.

Ruleworthy because: It's relatively easy to rip off a guy's helmet, and by that point it's just unfair. Oh yeah, you can also break someone's neck.

Famous incident: There were at least two facemask incidents in 2007 that invaded the personal privacy of players. Ohio State's Ross Homan tried to rip the head off of Washington QB Jake Locker with the traditional grab-and-twist move. Notre Dame's Travis Thomas and Mike Ragone roughed up Penn State's Jerome Hayes after they had pulled off his helmet.

HONORABLE MENTION: Tripping, clipping, head-first tackles, hair tackle (Larry Johnson grabbing Troy Polamalu's locks).