When to shield

Mine is a rather complex set of conditions, some that can happen on and off and some that can effectively disable shielding for the rest of the battle.  

I'm guessing you are more interested in the conditions that that turn it off for good.  That determination takes into account total bullet shielding misses, consecutive bullet shielding misses, average damage taken per shielding shot (presently it assumes all misses will result in damage, but I've been contemplating changing this to only when real damage occurs), overall shielding success ratio (total shielding hits / total shielding shots), and round number (some things more lenient on earlier rounds). 

More temporary on and off conditions include stuff like rolling average opponent fire power, opponent distance, round time, whether or not the opponent keeps not firing first, and whether or not a shielding shot was just missed.

If you want to see specifics, you can dig into my code and look at the big nasty condition starting on line 123 of BulletShieldingScenario.  It just might be the biggest condition statement I've ever written.  I need to do more research to figure out how often any of those conditions are actually triggered to fine tune it all and order the conditions to minimize processing required, but I don't expect a lot changes, other than cleaning up the class so it's not so messy.