Has the luck of the Irish run out?

World Heavyweight Champion Sheamus is a true master of the ring, an intense competitor who used his passion for fighting and unrelenting fury to become one of the top Superstars in WWE today.

Since claiming the World Title in a mere 18 seconds at WrestleMania, the first-ever Irish-born WWE World Heavyweight Champion has taken on all-comers in heroic fashion.

But at WWE Over the Limit, Sheamus will be challenged by Randy Orton, Alberto Del Rio and Chris Jericho in a Fatal 4-Way World Title Match. ( MATCH PREVIEW) Although such an encounter will, no doubt, be full of unpredictability, there is one thing that is fairly probable: The Great White not walking out of Sunday’s pay-per-view with championship gold around his waist.

The odds

Sheamus can tout his experience in championship Fatal 4-Way matches as proof he can handle himself in a four-sided fight at WWE Over the Limit. After all, he did seize the WWE Title from John Cena in that exact specialty match in 2010.

However, every numbers guru understands that past success has no bearing on future odds. By virtue of the match’s four-way format, the reigning champion starts at a disadvantage simply because he’s outnumbered by the challengers and because he himself doesn’t have to be the man pinned or submitted to lose the title. Because The Celtic Warrior’s Fatal 4-Way Match can end in any of 12 different ways but in only three that conclude with him retaining the World Heavyweight Title, Sheamus needs only to lose track of two of his three opponents to suffer the consequences.

In two of the three 4-way title opportunities that took place at pay-per-views after Sheamus seized the WWE Title at Fatal 4-Way 2010, the odds tilted toward the crowning of a new champion. At WWE: TLC 2010, Edge claimed the World Heavyweight Title from Kane in a Tables, Ladders & Chairs Fatal 4-Way Match. Eve also capitalized on a four-sided affair at the 2011 Royal Rumble to emerge the new Divas Champion. Only Dolph Ziggler upended his trio of competitors to remain United States Champion after Night of Champions 2011.

Two out of three title changes isn’t a bad record for the challengers, but three out of four would be better for Chris Jericho, Alberto Del Rio and Randy Orton at Over the Limit. With the odds and recent history trending for the challengers, expecting Sheamus to prevail would be a sucker’s bet.

His fierce fighting style

Any member of the WWE Universe can see that Sheamus’ ferocity and intensity strike fear into the hearts of his opponents. But the Irish powerhouse’s singular fierceness in the squared circle is more than his calling card; it could also be his downfall. As a true brawler, he has stated repeatedly that he loves fighting more than anything. Does that include winning?

The World Heavyweight Champion has never backed down from a fight, and he has never been in a scrap he didn’t think he could win. That gameness and confidence have led to great success in WWE, but those qualities could drag The Great White out of his depth on Sunday. In a grueling, hard-hitting Fatal 4-Way Match, there is something to be said for formulating a strategy, pacing  and playing the odds. Fortunately for Chris Jericho, he’s a ring General who always thinks this way. Unfortunately for Sheamus, he prefers to charge straight ahead and simply club everyone in his path.

This recklessness already landed him in hot water, as Executive Vice President of Talent Relations and General Manager of both Raw and SmackDown John Laurinaitis fined the temperamental pugilist a record $500,000 for Brogue Kicking referee Chad Patton after a controversial match on SmackDown last month. It was not the first time – and likely not the last – that The Great White’s emotions got the best of him.

There’s no denying that Sheamus is an impressive World Heavyweight Champion and a model Superstar. With an innate Celtic thirst for battle, he will bravely lay his title on the line against three of WWE’s most brutal and challenging competitors on Sunday at WWE Over the Limit. However, there is a downside to forever being the toughest guy who always wants the toughest fight: He just might get what he’s wishing for.

Sheamus loses his temper after his match with Alberto Del Rio.

Arm injury

Sheamus may have won the World Heavyweight Championship in 18 seconds, but his shoulder and elbow have taken an endless amount of punishment since The Showcase of the Immortals.

In his grueling 2-out-of-3 World Title rematch with Daniel Bryan at Extreme Rules, The Great White’s body was pushed to the absolutely brink. In the midst of that all-out war, his arm suffered the excruciating shoulder pain of the “Yes!” Lock, causing him to  lose the second fall.

When Sheamus faced the submission specialist again five days later on SmackDown, he ended up being locked in both Alberto Del Rio’s Cross Armbreaker which hyper extends the elbow and Bryan’s favorite maneuver yet again. Then, he returned to the ring in the main event that same night – bandaged up to the hilt – to endure even more pain in a second rematch against Bryan. Though he emerged victorious, the damage was clearly done.

On top of that, in the weeks since the WWE Over the Limit Fatal 4-Way Match was announced, The Great White’s has continued to suffer attack after attack from all three of his WWE Over the Limit opponents.

The World Heavyweight Champion has always been a natural target for abuse, as he stands on the top of the mountain, and no one could ever deny that Sheamus is one tough Superstar. But, just how much can the three-time World Champion take? The WWE Universe may find out this Sunday.

With Alberto Del Rio sitting at the commentary table, World Heavyweight Champion Sheamus and Daniel Bryan square off in the main event of SmackDown.

Randy Orton

Perhaps the biggest threat to Sheamus at WWE Over the Limit comes down to two words: Randy Orton.

Although a quick counter cost the third-generation Superstar his one-on-one match-up against The Celtic Warrior during the May 18 edition of SmackDown, The Viper didn’t leave the ring until he made a strong statement – dropping his red-haired foe with a surprise RKO after the bell. The spirit of his message was two-fold, “I am not a nice guy” and “I can strike and take your title in the blink of an eye.”

If this is indeed true, then who is more dangerous to the Irish Superstar than WWE’s Apex Predator, especially in the whirlwind atmosphere of Fatal 4-Way Match?

Orton is a nine-time World Champion for a reason, he knows how to win. He has cultivated a reputation as a specialist in squared circle chaos – precisely the sort of match he will enter this Sunday – and has the arsenal to back it up. Now that Orton’s intense pursuit of The Great White has become personal, Sheamus “may [just] need a bigger boat.”

World Heavyweight Champion Sheamus and Randy Orton face off one last time before Over The Limit.