Maybe you're unfamiliar with what I like to call "the art." I'm talking about the wristlock - it's one of the most underutilized yet devastating and effective submissions in competition grappling. You may be thinking "Well then why don't any high level black belts hit them in competition?" Well they do. Check out none other than, the animal himself, Jacare, demolishing this wrist:
And then there's possibly the coolest wristlock ever recorded on video: Marcelo Garcia v Weapon X at ADCC.
Have I convince you how lethal wristlocks are yet? Take a look at this video and learn the "the art" from Ricardo Cavalcanti (Carlson Gracie Team). He shows us a nasty wristlock from mount. It's a tricky setup that will likely have your opponent mistakenly defending the armbar, leaving the wrist for you to destroy (in a sportsmanlike way, of course).