Kickboxing vs. Shotokan: Observations
I don't know where this thread should go. Gitmo seemed conservative. I won't cry very much if you move it.
My experience: Two years of (Ohshima) Shotokan, a few weeks of kickboxing (and BJJ, but that's irrelevant to this thread). I thus do not claim any expertise in any martial art whatsoever (in other words, I suck).
I don't claim this is the least bit relevant to anything at all. I'm just nerd enough to find this sort of musing fun. Point 1.1 below might have some value; I don't know.
Just for the hell of it, to write down and catalogue and attempt to analyse the differences I notice in moving from Shotokan to (Muay Thai-like) kickboxing. (What does "Muay Thai-like" mean? Beats me; I'm paying for the BJJ and thought I'd check out the kickboxing class; it seems good to me but it's not like I've done extensive background research -- I get it for free with the BJJ membership, anyway. I do know that we do clinch-work, elbows, and knees, because we did that tonight. Bloody hell, I'm tired.)
1. Roundhouse kicks
I was kind of surprised to find that the roundhouse kick, as taught to me in karate, and the Thai-style roundhouse kick I'm now taught in kickboxing, is almost the same thing. With the dire reputation of the Thai kick, I thought the differences would be greater. All the same, the basic principles seem simple enough and identical: Get the leg up, cut down, leg straight when you hit, and spin through the target, not just bouncing off the surface.
The differences: In karate we spun around more or less as 'a unit'. In kickboxing we stick an arm out, then counter-rotate that against the rotation of the rest of the body (and hence the leg). Also, in karate, we chamber the kick (lead with the hip, but bend the leg at the knee); in kickboxing the leg is pretty much straight. (Should it be completely straight? I don't know, I'm a beginner.) Finally, the impact area differs in that we'd sometimes use the ball of the foot in karate. I won't go into that and don't find it very interesting.
1.1. Arm counter-rotation
When I was biking home from kickboxing it occurred to me why the counter-rotation of the arm might be a good thing. In karate someone occasionally made a vague mention of "Spin through with everything you have"; in kickboxing I've yet to hear an explanation. However, it became pretty obvious when it occurred to me (OK, I'm slow sometimes) that "spinning through with everything" doesn't make sense, because your body, when you're in the middle of a roundhouse kick, is not a linear but a rotating system, and so the physical principle of interest is the preservation of angular momentum, not linear. If you counter-rotate part of the whole rotating system, the rest of the system must therefore gain angular momentum for the duration of the counter-rotation in order to conserve the net angular momentum.
Conclusion: Counter-rotating does make you kick harder.
Why I'm an idiot for not seeing it sooner: Get on a fucking spinning chair.
1.2. Chambering the kick vs. straight leg kick
In terms of physical principles this one was rather less obvious to me. One of my problems with chambered round kicks is that I tend to lead too much with the knee, but that's because I suck; in karate (as I was taught), too, the leg should be straight on impact.
When starting the kick, and therefore starting to spin, it's much easier if the leg is chambered. On the other hand, you will slow down when you straighten the leg -- this one's obvious (again, get on a spinning chair, start spinning, extend and retract your leg; again, conservation of angular momentum). So which is better; the higher initial angular velocity of the karate kick, or the fact that in the Thai kick, you don't lose what angular velocity you already have?
Well, body mechanics aside (and that's a big aside), the one physical thing that's different (apart from air drag -- I expect it is far too small to matter) is static vs. dynamic friction. When you start to spin, you have the benefit of starting stationary and therefore 'pushing off' your rotation against your static friction with the ground. (The 'pushing off' is the only thing preventing you from conserving your initial angular momentum, i.e. standing still.) When you are in the middle of spinning, you are only decelerated by dynamic friction, which is smaller; hence the braking force acting against the loss of angular momentum when you straighten the leg is smaller.
Conclusion: Keeping a straight leg probably helps your kick get more power, although it's not clear to me how much. However, it also eliminates the chance of hitting the target while your leg is still bent.
2. The guard
The karate guard is lower and further out. Rather than ascribing this to sheer stupidity as is fashionable, I will only briefly speculate that it's a function of distance -- 'karate fighting' takes place at a somewhat longer range than kickboxing where strikes to the head will not come as quickly and reaction time is longer; perhaps it is valid to keep your hands lower to react more quickly to scoop kicks, etc. Perhaps not. In any case, as Ian Abernethy points out, karate kata have no guard, and think what you will of the value of kata today -- that is how the techniques were handed down before videos were around. The modern guard is a function of modern sparring. Modern karate sparring is longer-range than kickboxing -- etc. (Compare the karate guard to old-school bare-knuckle boxing guards, etc., etc.)
I can't punch. Ask any of my karate instructors.
More to follow, after I've learned some more, if I feel like it, if I remember too, and if you mean people don't flame me too much. Pre-emptive tears, etc.
Rather nice, I'd say. In regards to punching to punching and the lower extended guard in shotokan:
Hooks do not really exist in Shotokan matches, for a number of reasons. First and foremost, the referees seem to hate them and will not score them. Second, since excessive head contact can sometimes get you a deduction (this seems to be a variable rule in Shotokan competition), power shots are not a part of the game. Third, because of the point break, you are constantly restarting, and this causes the fight to take place at a longer range as you mentioned. Additionally, perhaps since hooking punches are not allowed/scored, most kareteka seem to go for sweeps when they get in a bit closer.
I'm rather wondering -- not why karate competitions are the way they are, because (I'm sure we'll all agree) non-contact sparring doesn't really tell you anything much about effectiveness: My karate instructors would refer to it as "a game of tag" and we spend very, very little time on it. Rather, I am wondering, how does the long/low guard of old-time bare-knuckle boxing compare to working guards in modern MMA? I understand that the old boxing rules were fairly permissive.