>SPOILERS IN REPLY<
Varian has actually bested Garrosh atleast twice now. Once in Ashenvale and once in the new book Tides of War. Garrosh pretty much enrages at the start of the fight and tries to enrage Wrynn with a comment about Anduin. Wrynn is shown to only grin in response before "dancing" around Garrosh, calculating his every movement.
For Varian:
Former Gladiator, more experience in life or death situations.
Avatar of Goldrinn, doesn't really do much to serve him in strength (I think?) It just means he's unrelenting and can fight for an almost limitless time.
Vengeance, an (Half) Orc killed his father in front of him. I know I for one would end up using that to fuel my rage, presumably someone in Varian's position would likely do the same.
A Father, he'll fight to get back to his son, reinforced by his statement during the pre-MoP cinematic where he says "We shall sail to this land, and find my son".
For Garrosh:
He's an orc, naturally stronger than Humans by nature.
Pride, he's a Hellscream. He believes he fights for the Horde.
I really can't think of any other reasons for Garrosh to win.
Since Varian has been blessed by a demigod I would say he wins.
Varian every time.
He's better equipped and has always been (Far more since Wolfheart) a more level headed fighter than Garrosh. On top of this he has Goldrinn's blessing. Also the last time they fought Varian won.
Less being misled and more being held in line through KGB-like fear tactics, as outright stated in Tides of War. Garrosh has been confirmed to be the last boss of Mists of Pandaria, while they're shifting most of the Horde's lore attention on Baine and Vol'jin (more Baine, at least in The Shattering and Tides of War), and Metzen stated he wants to shift Varian toward Lawful Good over MoP's timeline.
Be seeing you guys on Bloodsail Buccaneers NA!
Varian with his recent buffs. Before that I'd have given it to Garrosh.
The amount of threads like this xD
As good as I know I will say Varian. Altough if I didnt know a thing about warcraft I would say Garrosh due to him looking like a beast. He is twice the size of an orc.
I've always been an alliance lover, I preferred Horde when it came to the W3 Story and loved Thrall, but ever since WOTLK I've definitely leaned more towards Alliance (Guild is transferring back there this week!!).
But bias aside I still think Varian would come out on top, especially in a 1v1. Naturally every fight is different, but if the Wolfheart fight is anything to run off it felt like as if Varian had the upper hand most of fight, not only that but even bloody Cairne was able to beat Garrosh (He would have killed him if not for the Poison), if Cairne can beat him then Varian I think would certainly come out the victor.
Without the alleged supersaiyan-supersoldier-demigod buff that is Goldrinn's blessing, I think Varian still wins, he really just has more arena experience, and as their short 3.1 duel suggests Varian (pre-Goldrinn!) can hold his own strength-wise against the allegedly bigger and stronger orc.
Orcs are physically stronger than Humans and thus Garrosh has an incredibly big advantage over Varian.
The only way Varian has an edge is due to having more experience and by being a better tactician.
Then again, Garrosh did lead a succesfull campaign against the Lich King, so he does know a thing or two. (I know he does make mistakes)
Still I think that overall Garrosh is the most likely winner.
Blizzard may write that Varian wins, but it's not believable. Varian is puny compared to Garrosh.
Wasn't Varian some top-notch gladiator called 'Lothar' at some point?
I don't recall Garrosh having any special and incredibly demanding combat training other than, probably, the typical orc warrior training. A top-ranked gladiator should easily defeat that.
Also note: Orcs and humans are different. Orcs are much more bulky, and humans are more dense. Orcs weigh more, and can use this to their advantage when building up momentum. Humans are faster on their feet, though. Strength-wise, I don't think orcs and humans are too far apart. Different kind of muscle.
In the WoW d20 RPG, Orcs gain a +2 bonus to Stamina, meaning they're more durable, but also take a -2 penalty to Intelligence. Humans gain no bonuses, and no penalties. The end-result is that humans fight more on wits, reserving strength and planning their moves, whereas orcs go more full-out, relying on their body's endurance to carry them through. Pure strength-wise, though, the two are equal.
Apparently, Varian has some Deus Ex wolf blessing that grants him loads of endurance, meaning that Varian also has the physical edge over Garrosh.
Wrynn would tear Garrosh to pieces, even if Garrosh were hopped up on demonblood like his father.
Varian already almost won twice. Garrosh was saved by different reasons, in Ashenvale because of the magnataur falling for example.
The true question is:
Varian vs Cairne, who'd win in a fight? Alive Cairne of course.