Pirate vs Knight
Deadliest Warrior claims Pirate beats Knight.
Let's start my opinion with my credentials. I've been melee sparring in the SCA (a historical organization which also boasts very physical full contact melee combat sports) for going on 25 years. I have over 20 years of sparring experience in the medieval fully armored melee style of the 'knight', and more than 10 years of sparring experience in the Renaissance style of full contact fencing of the 'pirate'. I am extremely well learned in these styles, and have won many tournaments in both. I also love both of them equally, for what they are - which are two very distinct approaches to combat based on the weapons and armors available.
Short Range Offense
Knight - Broadsword
Pirate - Cutlass
The broadsword has a clear advantage here, in that it is a massive weapon compared to the cutlass, and if the cutlass is used to parry a broadsword, as is reflexive in the pirate's fighting style, the cutlass is going to break. The show mentioned that the cutlass has an advantage in closer quarters than the broadsword. That's absolutely false. First of all, the knight uses a shield in tandem with the broadsword, which is going to be next to impossible for the pirate to bypass to gain the closer quarters advantage. Secondly, one of the knight's greatest attacks is designed to be used in close quarters when another knight presses into close quarters with a shield rush. It's called a spot strike, and is a tight whipping motion that catches the opponent in the back of the head with lethal force. I have used this strike in melee combat sparring for over 20 years, and have had it used on me. It's incredibly effective. If the pirate presses the shield to the knight, the shield negates the cutlass, and the pirate is hit with the spot strike. If the pirate tries to grab the shield and pull it to create an opening, the pirate is getting nailed with the spot strike.
If that weren't enough, the pirate must also find a way to put that cutlass through the knight's armor. This just isn't happening unless the knight makes a ridiculous error. The knight's entire focus was to destroy opponents in melee combat, especially lighter armed and lighter armored opponents. All of the tricks up the pirate's sleeve were also up the peasant's sleeve - unbalancing, trying to get behind the knight, outmanuever, dirt in the face, etc. The knight was well prepared for all of these.
The pirate's best advantage here would be if he was a trained fencer with a rapier, which would allow him one strike to the eye slit of the knight's helmet before the knight was close enough to attack. While this may seem unrealistic, a well trained and experienced fencer can in fact pinpoint a dime in combat, and the eye slit of a medieval helm is more than twice that width. If the fencer can pull off this strike and get it past the knight's shield, he's likely going to kill the knight, because the knight is not going to be expecting the reach of the rapier, nor the precision, nor the tactic. If not, he's two peices of shark bait.
Long Range Offense
Knight - Crossbow
Pirate - Pistol
We could stop the argument at the fact that the pirate's pistol was unable to penatrate the knight's armor, but I want to take this a step further and make some important points. The force of a bullet fired from those pistols was equivalent to being struck with a stick rather forcefully. The knight would feel it, but it wouldn't unbalance him. The simulations showed a pirate carrying several pistols, and using them to knock the knight around. It just wouldn't happen like that. Small arms fire doesn't have that kind of force. It wouldn't begin to slow down an adrenalin charged knight, only piss him off and make him attack more effectively.
Compare this to the notorious accuracy and range of a crossbow, and there is no contest. Crossbows were lethal at far greater range than pistols, and even muskets. Muskets were terribly innacurate, unless fired at a line of troops, at which point they proved more effective than corssbows. In a one on one fight, there is no contest. Special Forces throughout the world still use crossbows, if you need a benchmark for effectiveness in single target situations.
Medium Range Offense
Knight - Halberd
Pirate - Blunderbuss
Here's where the show really missed the mark. Heh, that was a pun. The blunderbuss is a one shot, terribly innaccurate weapon. It's much like a short range sawed off shotgun. They were also prone to misfire, but let's assume that they never did. This is a one shot weapon that is most effective at a range of about 12 feet or less. In the simulation, a few of the pellets penatrated the knight's armor. No surprise there, due to the amount of gunpowder in the weapon. However, this is the important part, these are little pellets, which will not cause enough trauma to stop a combatant. If the shooter is lucky, very lucky, one of those pellets will hit an organ and begin the process of hydrostatic shock. Adrenalin will keep the fighter on his feet another 30 seconds to 2 minutes. And this is assuming the one shot is very lucky. Otherwise, at best it's going to inflict a minor flesh wound which is going to do nothing but bolster the knight's resolve.
Compare the damage of the blunderbuss to the massive trauma that can be inflicted by the halberd, which has effectively the same range, and does not run out of ammo, and this is a no brainer. Hehe, that's another pun. The halberd in the knight's armored hands is a much more effective weapon than the blunderbuss in the hands of an unarmored opponent.
Medium Range Offense
Knight - Morningstar
Pirate - Bomb
Again, the show failed. A bomb has a fuse, fairly high potential to be a dud, and a limited range where it can be thrown, but not harm the thrower. In other words, the bomb suffers from variable timing issues. In a combat situation where your opponent is bearing down on you, getting the fuse lit, throwing it, and getting it to explode at just the right time to injure your opponent is again a matter of luck. The two ways in which bombs are effective in this one on one fight against a knight are ambush and dismount. If the pirate can use the bomb to open up an ambush, then it is more likely that it will work, but still iffy. The best bet is to use the bomb to spook or better yet, injure the knight's horse and cause it to panic and / or dismount the knight.
On the other hand, the morningstar is an extremely deadly weapon when wielded from horseback. The mass and momentum of this weapon inflict incredible trauma upon any bone and tissue it makes contact with. The show claimed that the pirate had the ability to dodge the morningstar reliably, but when used correctly, unlike the demonstrators of the show, the morningstar moves about as fast as a thrown baseball. Not likely to be dodged, I am afraid. And the motion from horseback will cause upper body trauma in all cases. Not at all good for the pirate.
Defenses
Knight - Plate Armor
Pirate - None
This might be the most important point to mention that the show didn't. Modern people tend to look at 70 pounds of steel armor as terribly encumbering, restictive of movement, and most importantly causing visibility issues because they haven't spent years acclimating to it. As someone who has worn this stuff for years in sparring combat, I can assure you that these arguments do not have much weight. Ha another pun! First the armor was designed to distribute the weight very well, making it much less encumbering than one might assume. Second, and most importantly, the body adapts to the armor in several ways that after a few years make it like a second skin. Wearing the armor builds the muscles that bear it. Fighting in the armor teaches the body how to move in ways that are unimpeded by the armor, moving around the restrictions. Lastly, and surprisingly to many, knights used the mass of the armor against their opponents. It was part of their fighting style, and the biggest reason they were juggernaughts on the field. And for the record, the eye slit is in such a place where visibility is actually very good. You lose a little peripheral vision from the sides, and a fair amount of up/down which includes areas above your opponents' heads and below their knees. This leaves you a very effective field of vision. It is also assumed that getting a knight on his back would be akin to flipping over a turtle. Nothing could be further from the truth. Not only did knights train against getting unbalanced, they trained in getting up again, to such a degree that at the battle of Agincourt, the French knights held somersault contests in full plate armor the night before the battle, as they fully expected the English peasants to try to unbalance them.
All of that said... the knight will be a little slower than the pirate in a sword fight, but that's the only advantage, which will be entirely negated by any moves the knight knows reflexively. All of the spot strikes I've ever seen are as fast as any fencing jab.
Short Range Offense Tricks
Knight - Dagger (Not mentioned)
Pirate - Boarding Axe
The show also mentioned the boarding axe, then showed how it wouldn't have been able to penatrate the knights armor, but failed to mention that knights always carried daggers into battle because this was the most effective way to kill an enemy knight, by pinning him and thrusting the dagger through his eye slit. If the pirate did manage to unbalance the knight, and force him to fight from the ground, the pirate was going to be in for a bit of a surprise from the 'honorable' knight. who was extremely well versed in grapple and stab tactics, and would be able to physically overpower the pirate with both brute force and using the mass of the armor against him.
Training (Not Mentioned)
Pirate - Street fighters
Knights - Lifelong focused martial training
As always, this show never mentions the skill of the combatants. I understand that the assumption is that both combatants are 'at the peak of their game', but the distinction in what the peak of their game would entail is often a deciding factor. The pirate most likely developed his fighting skills brawling, and in a few real combats in which he lived. The knight was trained from birth in lifelong focused martial training. The difference here is extreme. The only way the pirate can compare to this is if somehow he was once a noble who was trained all his life in the art of fencing. Otherwise, the knight wins even this part of the contest hands down.
Knight beats pirate, unless pirate is lucky. There is no other solution here.