Weapon retention? Back to basics... Your absolute best bet first, before the party starts... is distance from anyone that might be an opponent, period. Once you're carrying a sidearm -it's as much of a danger to you as it is to someone that intends to attack... Our trainers could snatch a service weapon from the best retention holsters around years ago, face to face or from the rear... in training situations (I left police work in 1995) , maybe there's some new gear I'm not aware of but it's still on you to protect that weapon - and do your best not to get smoked with your own gun. If you must approach a possible opponent, or they approach you... turn your weak side (non weapon side towards them -the "interview stance" ) while at the same time moving your weapon hand to your sidearm - not to draw it, but to protect it while at the same time allowing you to draw it if needed... Even when not armed that's a standard maneuver for me. It puts that possible opponent on notice that not only you may be armed -but you're in a position to draw and defend yourself if needed. The fact that your "weapon side" is not visible to an opponent - nor your weapon hand... can allow you to bluff very effectively when you're not armed at all (and I've actually used that technique several times over the years since I've never carried a firearm from the day I retired from police work to the present...).
None of what I've described involves the martial arts - but the next part would be basic stuff for any martial artist - before striking, grappling, using a second weapon, etc. is simple footwork. Most of us even old guys like me have a bit of dancing in us - use your feet to keep the needed distance, and maneuver away from an assailant - aided by a simple push with your weak hand to keep the needed distance to prepare to fight or prepare to draw your weapon. Not much more to say except that, if carrying a sidearm - you really don't want to engage in a fist fight or a wrestling match - particularly with a younger more fit individual -who really really intends harm... Your best defense is to back off, break away, run if you must. It will at least provide the distance needed to make that shoot or no shoot decision if things get ugly.
Now for the next level.. you're facing more than one possible assailant... All of the above applies but with the added danger that you must not allow one of them to move to your side or even worse move to a position behind you. That's a very bad situation indeed since you can't defend what you can't see and more than one opponent makes it very likely that you'll lose any physical struggle if things get ugly... Here's a true story.. One of our officers, a very fit confident guy, more than capable in any fight, approached two young men in front of a closed store that had a silent alarm. Instead of keeping his distance until a back-up could arrive he approached and was talking with one of them and allowed the second guy to ease to his side. He never saw the punch coming and was out cold on the ground allowing the two to remove his sidearm from it's holster and prepare to execute him as he lay helpless... The only thing that saved him was an elderly couple walking their dog who approached and scared them off (still holding onto his gun - which we never recovered... ). Those two young men got away and we later und the breach in that store where they'd just done a burglary... I try to avoid war stories - but this type of encounter could happen to any armed citizen. A simple encounter might have found the breach in that store where they'd just done a burglary... I try to avoid war stories - but this type of encounter could happen to any armed citizen. A simple encounter might have some serious stuff going on - that you have no knowledge of and that might motivate an attack when you least expect it. Those basic tactics that I've just described might save you - without the "John Wayne" fight for your life... In my era a significant number of cops killed on the job - were killed with their own weapons in one encounter or another. This should be a concern for every armed citizen since the gun you carry might be your greatest danger...
