I don't really want to re-open this can of worms, but...
As a dedicated stand-up guy with zero ground skills (ok, not zero, but close enough!), as a guy who loves to spout out about how you should never got to the ground, and when there, getting back up is your first priority, as that guy, I've got to say this.
1. I put more time into the ground than my school in general, so that tells you something about how much my school is not ground fighters. However, there is a final portion of our test from Red belt to Black, the most strenuous test. You do all your pretty kata, you do sets of applied bunkai, a majority of them going to the ground, many of them with rudimentary ground defense, you spar for half an hour in continuous two minute rounds with fresh opponents, and THEN. Then, before you get your belt, the biggest black belt there gets on you in mount, and you have to get out from under to get your belt. The fact that a stand up school puts THAT as the coup de gras of the Black belt test shows what an absolutely essential skill getting out of mount is. If you've been mounted and you can't get out, unless your a skilled ground guy, you've lost. It's possibly the most dominant position you are likely to encounter, in general terms, aside from a back mount.
2. Biting. I don't discount it, but there are three major objections, no of them to be ignored.
-If you can bite, your opponent can bite, and if biting is your last ditch defense, you're already losing. Don't introduce the concept of biting at that point. There's a good chance he can bite something too, and if he's got control, he can probably bite something worse.
-Pain compliance requires, wait for it, compliance. We can quibble about whether a chunk of missing leg hurts more than a broken elbow, but in the end, he's missing some skin, you're missing a functional arm. You're gambling, hard core if you go the "who'll give up first route," and if the other guy's savvy at odds, he knows who has more to lose. Sure, bite if you have to, but don't in any way think it's likely to help you avoid getting your arm broken, neck cranked, or lose consciousness. So let's say it's an armbar, you bite a chunk out, he breaks your arm, you both scream and disengage, and stand back up to continue the fight. He just sacrificed a pawn for your queen. Can you still win? Yeah, but if you weren't doing well with two arms, i don't fancy your chances with one. And even if you do, a broken arm victory is Pyrrhic at best.
-Depending on where you bite, be prepared to lose teeth. I learned at, I don't know, about eight years old that if you're wrestling and a kid decides to chomp on a forearm, you don't pull away. You push in, you grind your forearm into their mouth, and quickly they decide that the last thing they want in their mouth is your arm. If it's a leg, you better hope they don't twitch and bash your teeth in, and your head of the floor.
The takeaway is this. If you're truly training for self defense, and if you want to be able to fight at your preferred range, you need to learn a bit about the other ranges.
Closing distance on a ranged striker is far easier and requires far less knowledge than beating a ranged striker at long distance. If you're not a ranged striker (I'm not) learn enough to survive there for two seconds and get to your preferred range. Or run, they're already six feet away!
Getting space from a close fighter, or taking them down is far easier and requires far less knowledge of infighting than beating an infighter in a clinch. I know. I'm pretty good at fighting from anything in the range from chest to chest to about three feet away, especially if I have contact. break contact and create space, and I'm in trouble. Take me down and I'm in trouble. If you're not an infighter, learn enough about clinching and arm control and restricted striking to survive for two seconds and get to your preferred range.
And finally, this is the one where we seem to run into trouble in the upright fighting world. If you're dealing with a ground fighter, there's a solid chance they can take you down. You need to know what to do when you're down there. Now, you don't need to know enough to win a ground fight against a ground fighter on the ground. To do that, you need to be a better ground fighter, or lucky. (Or insanely vicious, that unfortunately counts for a lot.) But you do need to learn enough legitimate ground fighting to survive for a few seconds and get back on your feet.
You wouldn't substitute biting at flying fists and clawing and groin strikes for a bit of training in ranged striking, because at that range, the ranged striker can do all those things better. You wouldn't substitute those "dirty" tricks for in fighting, 'cause guess what, if you're not an infighter, we can do all those things better when we're locked up close, and we can better position your teeth where we want them.
So you can't expect it to be a viable strategy against a ground fighter. Ground fighting is the range at which the skilled practitioner has the most control, because the ground is a wall severely limiting movement. If you can't control them enough to not get mounted, arm barred, choked, etc, then there's a good chance they can control you enough to not get bitten, or at least to bite you somewhere better.
Now, should you completely discount bites? No. They're a weapon, if a messy one. I wouldn't suggest removing any other pain compliance from your repertoire either. But it is simply not going to substitute for a modicum of skill in the various ranges.
Especially when it comes to ground fighting. Ground fighters are fast, but the pace and duration of a ground fight is generally far slower and more drawn out than upright fights. This gives people more time for clarity of thought. Sudden pain from a bite in a strike fight might give you that split second of pause to get in a good chin shot, especially since minds are racing and things are moving at 50 miles an hour, or however fast fists travel. In a ground fight, the better fighter can immobilize things to the point where not much is moving. The amount of mental clarity is higher, and your bite might create a much more rational reaction, in other words, not a spazzy flinch, but a concerted determination to hurt you more, and faster.
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I just want to say once more, I'm a stand up guy. I suck at the ground. But really, if you want to have some answer to being mounted, learn a little bit about the ground. You don't need a BJJ black belt, but you do need more than agility, struggling, and biting.