so like with blood, if you use a longer blade like a machete etc or just a hammer, you are not likely to get a ton on you, you are thinking like that because you basically are in boxing, clinch, hugging range with a knife, this is super undesirable if you can avoid it because it allows even an unarmed person to attack you back, you want to attack successfully and harmfully without being attacked back or grappled, knives are mostly good for concealment or if you get grappled pulling one fast as a get the fuck off combo breaker measure, at which point best know some anatomy like artery and tendon positions etc or caveman stab into the skull like varg if you're that guy  recall there are large arteries in the inside of th leg, under the collarbones, and on the inside of the armpits/inner upper arms, if you have access to any of that tear it up, everyone knows more obvious ones
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