Punching, Kicking and Getting Your Bell Rung

At some point I really want to make a gritty sub-system or rules light variant of network for unarmed fighting. This wouldn't be for Ogre Gate (which is a lot more high action) but something you might throw in a Crime Network or Servants of Gaius session. When I have time I will sit down and flesh out that system. 

For the time being I've been thinking about optional rules for getting your bell run after someone strikes you unarmed (keeping in mind this would naturally also be applicable to being struck with a melee weapon since if you can knock someone out with a fist, you should probably be able to do so with a baseball bat as well). 

Getting your bell rung is something you hear about a lot in different full contact martial arts (whether its boxing, kickboxing,etc). Basically its what happens after someone lands an effective combo or even a well placed shot. You are shaken and another solid hit or combo could knock you down. This can be a bit on the tricky side to model, and I want to simplify for gaming purposes.  

What I am thinking now is to tie it to our Total Success mechanic. For every Total Success you get on a melee or unarmed attack roll the target has their bell rung for 1 round. When you're bell is rung, then any additional Total Successes on attack rolls against you, knock you out for one round each if you fail an Endurance Roll TN 6. Or maybe you stay knocked out until you make another Endurance roll TN 6 (rather than have it last 1 round per Total Success). 

This would only be on the attack and not the damage roll. I thought of doing the damage roll first, but didn't want to muck with wounds and I felt this was more about precision and timing of the strike.