What is it exactly that turns so many professional sportsmen into jerks? The question has been posed for decades, perhaps even centuries now, and no one is yet to come up with a perfectly straight answer.

Perhaps it's the money. These guys, particularly those at the top, are being paid very good coin to do what they love, be it throw a football, hit a baseball, kick a soccer ball, punch the guy opposite you in the ring, and so on. The money they earn is astronomical, and often leads to superficial lifestyles and a tendency to behave above the law.

Perhaps it's the fame. These guys are revered, even worshiped, by supporters across the globe. Manchester United for example claim to have more than a billion supporters worldwide. That kind of fame is usually reserved for the Pope or the royal family. This notoriety means a lot of these sports stars can't lead normal lives, because they can't walk down a street without being mobbed. After a while this kind of thing gets tiring, and many of these sports stars can't handle the extra attention. This can lead to anger and sometimes even aggression.

Maybe it's the egos they nurse. If you're at the top of your game, one of the best in the world, it's easy to fall into the trap of thinking you're a superior human being. People love you purely because of your talents. You're earning a stack of money because of your skill, and let's face it, you just love showing it off when you get the chance. Far too many sports stars are jerks for any or all of the above reasons. Unfortunately, they're not all Roger Federers.

Here's the top 15 beloved athletes who are jerks in real life.

15 15. Pedro Martinez

Martinez was a three time Cy Young Award recipient and will be forever loved by Boston Redsox fans after the role he played in delivering their first World Series win since 1918. He was a magnificent pitcher, and wore his heart on his sleeve throughout a career spanning almost two decades. But a moment of madness in 2003 cemented his jerk status. During a feisty game with the New York Yankees, an altercation broke out and 72-year-old Yankees bench coach Don Zimmer charged at Martinez. The pitcher, roughly 40 years younger than Zimmer, grabbed his adversary by the head and threw him to the ground.

14 14. Buddy Franklin

He's been the most dominant Australian Rules footballer for a decade and left Hawthorn for Sydney at the end of 2013 after signing an unprecedented nine year contract believed to be worth more than $10 million. But he possesses an ever expanding rap sheet and can't stay out of the celebrity obsessed Sydney media. Put it simply, he's a pretty wild kind of dude. During his Hawthorn years he was appointed a driver, a teammate who was tasked with ferrying the big forward around Melbourne and generally keeping an eye on him. That didn't stop him incurring a speeding charge in 2012, or becoming involved in a heated argument with a woman in 2013. He was back behind the wheel again in 2014 and once more it didn't end well. He smashed his girlfriend's $70,000 into four parked cars. No doubt there's plenty more juice on Franklin the media hasn't quite uncovered just yet.

13 13. Manny Pacquiao

The superstar Filipino boxer was thrust into the headlines just recently for homophobic comments made at his training base. He was forced to apologize after saying animals were better than gay people because "They can distinguish male from female." His apology lost all credibility when the following Bible quote appeared on his Instagram page, before being swiftly deleted.

"If a man has sexual relations with a man as one does with a woman, both of them has done what is detestable. They are to be put to death; their blood will be on their own heads." Get with the times Manny.

12 12. Michael Phelps

He's the most successful Olympian of all time, and won an astonishing eight gold medals at the Beijing Olympics in 2008, but America's golden boy of the pool isn't exactly an angel when he leaves the water. He's twice been busted for drunk driving, most recently in September of 2014 when he was pulled over for exceeding the speed limit by almost 40 miles per hour. Police found he was also well over the blood alcohol limit. Fortunately, no other motorists were harmed during his drunken escapade. In fairness to Phelps he has been very philanthropic throughout his ultra successful career. Perhaps he just suffers from extremely bad judgement.

11 11. Babe Ruth

A revered icon in American sport and believed by many to be the greatest baseballer of all time. He was one of the first inductees into the National Baseball Hall Of Fame and set many MLB records, some of which still stand today. Away from the diamond, Ruth was just as prolific when it came to extra marital affairs with women. He married young and adopted a daughter, Dorothy, with his first wife. Dorothy revealed many years later that she was in fact Ruth's biological daughter, and her mother was one of Ruth's many mistresses.

His first marriage eventually fell apart and he married again about four years later. He was married for most of his baseball career, but still famously once said "I promise to go easier on drinking and to get to bed earlier, but not for you, fifty thousand dollars, or two hundred and fifty thousand dollars will I give up women. They're too much fun." We're tipping he might not have got away with this kind of behavior had social media been around back then. As much as we all love Babe for what he did for baseball, it's hard to defend his off field conduct.

10 10. Tiger Woods

It's safe to say Tiger isn't quite as beloved as he once was. Mind you he still does have a lot of fans in the golfing world, particularly in America. That's because his career, save the last six or seven years, was possibly the greatest in the history of professional golf. He spent more time at World Number One than any golfer has before or since, and his 14 major wins is second only to Jack Nicklaus. But he hasn't been anywhere near his old self since late 2009 when a series of media reports led him to admit to years of infidelities. Streams of women came out claiming they'd had an affair with Woods and it led to him and his wife getting a divorce. He hasn't won a major since.

9 9. Floyd Mayweather Jr.

Unbeaten in all 49 career starts and the best pound for pound boxer of his generation. His achievements in the ring have elevated him to boxing's elite and he's worshiped by fans of the sport across the globe. Unfortunately Mayweather never learned during his career that once he steps outside that ring, the gloves are meant to come off. He's been charged with battery countless times, and it's usually the fairer sex he beats up in his own time. Most often its ex-girlfriends and sometimes in front of their kids.

8 8. Brett Favre

Favre is a Green Bay Packers legend and one of the most enduring quarterbacks the NFL has seen. He started roughly a million games in a row and even played alongside Vince Lombardi. Well not quite, but it did seem like he'd been playing forever when he eventually retired. Unfortunately his reputation was badly tarnished towards the end of his career. Never mind what seemed to be an unwillingness on his part to hand the reins over to Aaron Rodgers when he was getting a bit long in the tooth. He finally left, went to the Jets, and Rodgers blossomed.

While Jets quarterback, a married Favre seemed quite taken by ex model Jenn Sterger. When he unsuccessfully tried to coerce her on a date he went to plan B and allegedly texted her some pictures of his penis. That failed too, but did land Favre in the national headlines while doing irreparable damage to Sterger's sports journalism career.

7 7. Ty Cobb

Another baseball legend, and another legendary jerk. He entered the inaugural Hall Of Fame alongside Babe Ruth and finished his 22 season playing career as one of the great batters the game has produced. He could steal a base too. But look past all of those impeccable numbers he produced on the diamond, and the real Cobb emerges. He was a violent racist who enjoyed beating up on people when the chance arose. One day he took to a black groundskeeper who he'd known for years after the groundskeeper attempted to shake his hand. He then started choking the groundskeeper's wife when she intervened, until teammates pulled him away. A year later he assaulted a black laborer. A few years later he assaulted a fan who was missing one hand entirely, and most of his second. I could go on and on.

6 6. Ray Lewis

What do you think of when you read the name Ray Lewis? Probably something along the lines of linebacker, awesome tackler, Super Bowl winner, Baltimore Ravens legend, and so on and so forth. What you should really think of is a white suit. Some of you will know exactly what I'm talking about. Others will have spent the last years either blissfully ignorant, or a victim of the superstar athlete phenomena where someone's sporting achievement seems to override serious indiscretion of their personal life.

In early 2000, Lewis and his friends were involved in a fight that led to two stabbing deaths. Lewis and his friends were charged with murder but the evidence wasn't there to build a complete case. Curiously, the white suit Lewis was wearing on the night has never been found. Investigators did manage to find blood from one of the victims in Lewis' car.

Two weeks into the trial Lewis negotiated a plea agreement where he pleaded guilty to the lesser charge of obstructing justice in exchange for testimony against his two companions. Lewis admitted he had lied about his presence at the murder scene when he was first questioned by police. The murders remain unsolved and Lewis remains a free man in NFL retirement.

5 5. Diego Maradona

We've all heard of Maradona, soccer's second greatest ever product behind Pele, the Hand Of God, the best dribbler we've ever seen and so on and so forth. But he's a bit of a menace off the field. That's an understatement actually. Maradona was driving to a press conference in Buenos Aires back in 2010 ahead of that year's World Cup. He was surrounded by cameramen and one of these unfortunate souls was knocked to the ground. Maradona then ran over the cameraman's leg, before shouting "What an asshole you are!" "How can you you put your leg there where it can get run over, man!"

Turns out he's something of a repeat offender. Last year while playing in a charity match, Maradona scored a late penalty which proved to be the winning goal. He went over to celebrate with fans, but was held back by stewards and surrounded by cameramen. He lashed out at one of each, earning a red card for his actions.

4 4. Michael Jordan

The greatest basketballer of all time, and now a billionaire owner of the Charlotte Hornets. He dominated on the court earning the nickname 'His Airness', and won six championships with the Chicago Bulls. But since his retirement, Jordan's true colors have slowly been revealed. It turns out Jordan had a lover on the side of his marriage during his playing career, a woman he paid $250,000 to keep quiet about their affair. On top of that, as an owner of the Hornets, he has thrown his power around on occasion to the detriment of the players. During the lockout negotiations a few years back, Jordan was leading the charge on reducing the income earned by players. Income he earned so handsomely during his own days and income which he now uses to fund his NBA owner power trip.

3 3. Kobe Bryant

Retiring Lakers great Kobe Bryant has enjoyed an outstanding career in L.A. where he's spent the past 20 years. His legacy will be substantial and he'll long be remembered as a true Lakers and NBA great by fans in the city and across the country. But his reputation was forever tarnished in 2003 when Bryant was accused of the sexual assault of a 19 year old hotel worker in Colorado. The incident allegedly took place the night before he was due knee surgery. Bryant maintained his innocence throughout claiming his actions were consensual, and apologizing profusely to his wife. The case was dropped the following year and an out of court settlement with the victim reached.

Bryant's actions off court at the Lakers throughout his career also justify his inclusion in this list. After the Lakers lost the 2004 NBA Finals, Shaquille O'Neal was traded to the Miami Heat. Many fans still blame Bryant for Shaq's exit given the pair's strained relationship. Bryant meanwhile signed a huge seven year contract to stay at the Lakers. Three years later Bryant publicly expressed his desire to be traded away from the Lakers before changing his mind. During this time a video surfaced showing an angry Bryant saying that teammate Andrew Bynum should have been traded away. Not exactly the epitome of a team player.

2 2. Ryan Giggs

Ryan Giggs was revered at Manchester United for his loyalty and commitment during an astonishing 672 game career between 1990 and 2014. But United fans are conveniently forgetting one thing when they put Giggs up on that pedestal. Like several of the athletes on this list, Giggs indulged in extra marital affairs during his playing days. One of those lasted for eight years which is bad enough, but here's the thing. He was sleeping with his brother's wife. She even claims to have aborted a child belonging to Ryan just weeks before marrying his brother. Giggs's brother and his wife divorced in 2013.

1 1. Zlatan Ibrahimovic

One of the world's most celebrated soccer players, but you would be hard pressed to find a bigger jerk in world sport. Zlatan's main problem seems to be that it always has to be about him. Quite often to the detriment of his own teammates. Perhaps a quick list would be best to collate some of his indiscretions over the years: kicking a teammate in the face, threatening to break a teammate's legs, threatening to publicly beat up his manager, beating up teammates at training, kicking and stamping opposition players, abusing officials and outrageous sexism.

In all seriousness, some of the behavior he's displayed over the years is beyond belief.