For as long as sports have been around, so, too, has the effort to gain an edge on the competition. Sometimes, this involves noble endeavors such as training hard, practicing endlessly and addressing facets of your skill set that require some fine-tuning. Other times, however, the effort to better one's result and one's standing in a sport can be a little more under-handed. Sports are nothing if not competitive in nature, so those desperate to remain in step with their rivals can - and have - turn to nefarious, illegal means of one-upmanship.

For some, the temptation to cheat can be understood, if not condoned. A minor league baseball player, for instance, may recognize that his only possible path to the major leagues - and, with it, major league pay days - is to 'juice up' and partake in a steroid regiment. Less understandable, though, is the need for elite superstar athletes to cheat. Ostensibly, their natural talent has elevated them into a rarefied air which helps them reign as one of the very best at what they do.

Intriguingly, this list is comprised exclusively of athletes who had already achieved greatness when they opted to journey down a dark path to cheater-dom. It's always possible that these superstars had gone undetected as cheaters for a time up until they no longer could. That logic may hold up as being plausible for old-time cheaters on this list, such as Ty Cobb, Whitey Ford and Gaylord Perry. But that logic begins to stretch credulity as we enter the modern era of TV-fueled scrutiny, media intensification and technology-driven testing procedures.

Whether these cheating athletes were doing so for the first time or were finally caught after a lengthy history of sly practices, they all share a common trait as superstars whose deceitful trickery was ultimately exposed.

15 15. Whitey Ford

There's almost an old timey charm to hearing about the good, old fashioned trickery of baseball's olden days. The standard response to the cheating ways of Yankee great Whitey Ford, for instance, leans more towards a chuckling bemusement than the moral outrage reserved for modern cheaters. Among Ford's alleged indiscretions, he supposedly used his wedding ring to cut the ball, got his catcher to slice it with a buckle on his shin guard and planted mud pies around the mound in order to load the ball. In fact, he confessed to using "enough mud to build a dam" while pitching against the Dodgers in the 1963 World Series.

14 14. Stella Walsh

Stanisława Walasiewicz, or Stella Walsh, was the toast of Poland after claiming gold at the 1932 Summer Olympics in the women's 100-metre event by matching the world record of 11.9 seconds. Returning home a celebrated hero, she was awarded the Golden Cross of Merit. It was only after her death in 1980 as the victim of an armed robbery that an autopsy revealed that she possessed both XX and XY chromosomes, along with male genitalia. While the rules on trans-gender Olympic participation have always been murky, particularly back in 1932, Walsh clearly wasn't forthcoming as she enjoyed years of celebrity.

13 13. Boris Onischenko

Heading into the 1976 Montreal Olympics, Russian modern pentathlon world champion Boris Onischenko was one of the key athletes to watch as a star in the twilight of his career who was looking for one final medal. Onischenko had helped his country to a fourth-place standing as they entered the fencing component of the event, which they were expected to dominate. During the fencing competition, however, it was found that the Russian team had re-wired the epee to produce false hits when Onischenko hadn't recorded one. Upon the revelation of the faulty epee, he was immediately disqualified from the Games.

12 12. Thierry Henry

For the many sports fans opposed to the inherent corruption within FIFA, the infamous Thierry Henry handball that gave France the victory over Ireland in a 2009 World Cup qualifying match is the gift that keeps on giving. It was revealed earlier this year that FIFA had paid the Irish Football Association $5 million to evidently put the incident behind them. The validity of the handball is tough to question, given that Henry even admitted shortly afterward that he had, in fact, handled the ball. Irish supporters outraged at the time were undoubtedly displeased to know that their national federation took money in the aftermath.

11 11. Gaylord Perry

Hall of Fame pitcher Gaylord Perry was never particularly shy about acknowledging his reputation as one of the game's foremost spitball-throwing pitchers. He even went so far as to title his autobiography, Me and the Spitter. This represented an odd piece of bragging for a guy whose notorious pitch had been outlawed in 1920, 42 years before Perry reached the majors. Still, it came to be well known that Perry would add Vaseline to his uniform under the bill of his cap, in his waistline or even under his sleeve in order to throw the illicit, difficult-to-predict pitch.

10 10. Hansie Cronje

Hansie Cronje was probably the most famous cricket player in the world in 1999 when police in India revealed that the South African national team captain was caught on tape negotiating the throwing of matches for thousands of dollars. According to the police, Cronje had been tipping off a known gambler prior to a match between India and his South Africa team. The all-rounder was handed a lifetime ban for match-fixing, which he continued to fight until his death in 2002 in a plane crash.

9 9. Paula Radcliffe

Steroid abuse aimed at gaining a competitive edge is becoming sadly commonplace in modern sports, but British long-distance runner and marathon world record holder Paula Radcliffe took things further by the sheer hypocritical nature of her doping. Radcliffe has used her celebrity as an outspoken anti-doping activist, protesting at events and has openly called for harsher sanctions on dopers. Earlier this year, though, it was her name that was part of a list of athletes with "suspicious blood values". She has denied the allegations, but remains unwilling to release her blood test history.

8 8. Ty Cobb

Probably the preeminent villain in baseball history, the un-apologetically racist and surly Ty Cobb also ranks as one of the best players of all-time. But he certainly didn't get there through clean, honest and fair play. The widely reviled "Georgia Peach" was known in his heyday for cleating infielders, stealing signs and even tripping base runners in a time before the presence and scrutiny of TV cameras. With steroids still decades away from human use, Cobb employed just about every under-handed tactic available to him.

7 7. Diego Maradona

Nearly 30 years later, Diego Maradona's famed "Hand of God" goal in the 1986 World Cup for Argentina might hold up as the most controversial score in soccer history. In a quarterfinal game against England, the Argentine superstar swatted the ball into the English net, but appeared from the angle of referee Ali Bin Nasser to be a header. The goal helped Argentina to an eventual 2-1 win en route to the World Cup title. The iconic "Hand of God" phrasing would come from Maradona, himself, who explained the goal after as, "A little with the head of Maradona and a little with the hand of God."

6 6. Mike Tyson

It is a standard staple of many boxing fights for the two participating pugilists to get tied up, pulling each other in towards one another to prevent either one from landing a serious blow. Despite that, few boxers have taken the path that "Iron" Mike Tyson did against Evander Holyfield on June 28, 1997. In a heavily hyped WBA Heavyweight Title rematch between the two legendary boxers, Tyson bit down on each of Holyfield's ears, spitting out a small chunk that had been disgustingly removed from it. The bite heard 'round the world left Tyson with a lifetime ban and continues to live on in infamy.

5 5. The Mitchell Report Group

We could break down each of these guys individually, but they all follow the same theme of being MLB supermen who put up huge numbers, only to later be felled by their inclusion in the Mitchell Report. Among those identified in the 2007 list of 89 alleged steroid abusers, most of whom categorically denied the allegations, were baseball icons like Barry Bonds, Mark McGwire, Sammy Sosa, Rafael Palmeiro and Roger Clemens. Some of these players, including McGwire and Sosa, were called in front of US Congress to investigate the use of anabolic steroids and PEDs in baseball.

4 4. Tonya Harding

There are sports rivalries and then there were the lengths that American figure skater Tonya Harding went to in order to get rid of her countrywoman and rival, Nancy Kerrigan. Through her ex-husband Jeff Gillooly, Harding conspired to have a hired thug attack Kerrigan's leg at a practice session for the 1994 US Figure Skating Championships. Harding won the event after Kerrigan was forced to withdraw, but Kerrigan returned in time to get revenge by winning silver at the Lillehammer Olympics that year. Harding finished eighth at the event and later plead guilty to the attack.

3 3. Tom Brady

New England Patriots superstar quarterback Tom Brady has largely been vindicated for his involvement in the much-hyped Deflategate, a controversy that has ultimately reflected more poorly on NFL Commissioner Roger Goodell. Still, it's tough to believe that Brady was completely in the dark while other members of the Pats organization took it upon themselves to deliberately under-inflate balls ahead of the 2014 AFC Championship game against the Indianapolis Colts. Wouldn't a veteran quarterback notice a change in pressure from the pigskin?

2 2. Lance Armstrong

Few narratives are as likely to turn an athlete into an American hero as seven consecutive Tour de France victories after conquering cancer. So it was little wonder that Lance Armstrong went to such great pains to preserve his public image in the face of countless accusations of doping improprieties, dragging down and smearing friends and teammates along the way to protect himself. Eventually, the accusations caught up to Armstrong, who finally admitted to doping in 2013 under the weight of federal and USADA investigations into his doping practices.

1 1. Alex Rodriguez

Alex Rodriguez's name was not found in George Mitchell's 2007 report, but that represents one of the few times when A-Rod has not been connected to performance-enhancing drugs. Rodriguez, himself, went on 60 Minutes in 2007 to proclaim his innocence to host Katie Couric. However, after a 2009 Sports Illustrated report identified him as one of the positive tests that emerged during MLB's 2003 survey testing, he changed his tune and admitted to steroid abuse in the early 2000's. Even then, though, he claimed that he hadn't taken anything since that time, only to later be linked to the more current Biogenesis scandal.