The Combat Speed Fallacy is a dishonest and flawed argument used by various posters (usually DBZtards such as the Phenom Brigade and MvC wankers). The essence of the argument relies on trying to categorize every speed feats of the other side as "travel speed", "movement speed" or some other kind "non-combat speed". They will then proceed to claim all of those speed feats don't count and their favored character would speedblitz the opposition. This is fallacious for many reasons.
 
First of all, said wankers never give a consistent definition of "combat speed". Realistically, to fight at a certain speed requires no more than the following:

- The ability to move at that speed
- The ability to perceive an opponent moving at that speed
- The ability to react at that speed

So logically, demonstrating "travel speed" feats in combination with sensory and reaction/thought speed feats should be sufficient to establish a character's "combat speed". However, the trolls who use this argument almost never accept this, instead trying to define "combat speed" as something that can only be measured in combat, which is retarded.

Some of them then take this even farther, claiming that fights that cover large distances don't count as combat speed, but travel speed, as the combatants were traveling while fighting. A notable example of this kind of sophistry was when Phenomenol claimed that the instance where Wally West fought Zoom II all across the Earth multiple times in less than a second didn't count as combat speed, despite the fact that they were exchanging punches and attacks the whole time. Hilariously, he then went on to claim that Goku using IT to arrive at the island where Cell was fighting and saving his friends, then IT'ing back out before Cell could attack him, did count as combat speed, despite the fact that no actual combat occurred.

Another problem with the "combat only" definition of combat speed is that in a fight that does not cover significant distances, there is usually no indication of the actual speed the fighters are moving at. Barring narration saying something like "X moves his fists at the speed of light", "Y throws 1000 punches per second", or "Z strikes in less than a nanosecond", a visual depiction of a fight (especially in sequential art) is almost always unquantifiable. Further irony arrives from the fact that such narrations are the kind you would most likely find in a western comic book, as opposed to a manga or anime, which is the side the users of this fallacy usually support. This is why most calculations done for character speeds are based on feats against known variables (i.e. bullets or things falling due to gravity), not fights.
 
One might then wonder how the supporters of this argument quantify the "combat speed" of their favored characters. There are usually two tactics they use for this:

- They don't bother to quantify it at all, they just say it must be super fast because it's drawn with a lot of blurry lines and afterimages or the fact that background characters can't see the fight happening. When shown similar examples of blurry drawings, afterimages, and disappearing from sight from their opposition, they simply dismiss it with a line like "So what, Kid Goku was doing that at the beginning of Dragon Ball"

- They actually use (or attempt to use) quantifiable speed feats to determine the speed of their characters, and then assume they are using their absolute maximum speed during combat, while if a comic debater makes the same argument they ask him to prove the character was fighting at the same speed of his other feats.

As you can see, this whole line of reasoning is based on blatant hypocrisy and double standards.

But I'm just getting started:

There are many times when a character's "travel speed" feats apply equally for determining their "combat speed". Situations where characters are fighting while traveling have already been mentioned, but another scenario is where they are traveling through an area filled with obstacles. Obviously if they could not perceive and react at the speeds they travel at, they would be bumping into things all the time. Any character that runs around a planet or other large distance on the surface of a planet or moon should be given "combat speed" equivalent to their travel speed by default, due to having to see and dodge all of the obstacles in their way. Wankers who use this fallacy never accept this, though.

Another way for a character with only high demonstrated "travel speed" to be considered high in "combat speed" is that character's senses. Heralds of Galactus, for example, are often stated and shown to sense things at FTL speeds over vast distances, often described in terms like "being able to sense a single dust mote from another galaxy". Obviously a character with senses on this level will have no problem detecting and countering an opponent attacking at comparable speed to their own.

Even if we were to accept that a character can't perceive or react anywhere near as fast as they can physically move (and this is rarely true of any characters in fiction), the character with the faster movement speed still has the advantage. This can be demonstrated as follows:

Say Character A has a movement speed and combat speed of 1,000, and Character B has a movement speed of 1,000,000 but a combat speed of only 100. There are still many winning strategies for Character B, for example, bumrushing Character A at maximum speed. If Character A can't get out of the way in time, then he's dead (assuming Character B has the power to hurt him). Even if Character A manages to dodge, Character B can simply continue on his path until he has reached a safe distance from Character A, then re-aim and try again. Eventually he's bound to land a hit.

Another strategy would be attempting to grab one of Character A's limbs, this might take a while but once it is done, Character B can use his superior speed to take Character A with him into a dangerous place (outer space, a star, etc.). If the speed is high enough, Character B might even be able to rip off Character A's limb. In addition, a character that has one of more of their limbs immobilized cannot escape or dodge effectively, thus negating the "combat speed" difference.

Obviously the specifics of the characters' powers, the battle arena, and various other factors can influence scenarios like the ones above, but it is a good general overview.

As of Spring 2012, this fallacy seems to be making a resurgence in the OBD, giving certain threads a MvC or CBR feel. Hopefully this unfortunate turn of events will cease (as if, well actually, it seems to be more a recurring thing nowadays).

 

As of Spring 2016, this fallacy seems to have disappeared in the OBD (for now).