jshuberg wrote:I have absolutely no disagreement. A person should absolutely train for a variety of conditions, including adverse or compromising conditions.
For a new shooter though, I recommend minimizing all of the variables possible so they can focus of the basics of trigger squeeze, sight alignment/picture, follow-through, etc without other issues getting in the way. An asymmetrical stance can have the effect of introducing errors that can complicate becoming proficient at the fundamentals. Specifically, shooting with asymmetrical shoulders or arms tends to make follow-through and rapid-fire a more difficult skill to acquire. Once a person becomes reasonably proficient, he should then begin introducing alternate stances or positions, wrong hand, wrong finger, wrong eye, etc. My point about minimizing your thickness to the target or squaring yourself with a vest was to explain that adopting a isosceles or modified isosceles stance does have applications beyond simply training to master the fundamentals.
There is no right or wrong answer, everyone is different and responds differently to different techniques. That being said, those people I've shot with who have had martial arts training did in fact progress more quickly after switching to an isosceles stance. YMMV.
jshuberg: yes... and...
Upper body mechanics overtake foot placement in importance during reaction to a dynamic situation threatening imminent death. Start this video at 5:10.
http://www.youtube.com/watch?v=9bLUB2MMMeI Watch through to at least 6:31.
Don't discount the value of moving while shooting
http://www.youtube.com/watch?v=zDm9eHwfOqg. Many bad guys are within physical striking distance, or have accomplices, and there's no rule that in the streets, unlike Hollywood, the bad guy drops like a wet sack of flour at the moment the first bullet impacts. Plus, we draw the gun as our LAST resort, right? So, the situation by that point may have evolved, and everyone's moving/fighting at physical contact distance.
That said, I wholeheartedly agree that, for beginners, it's ALL about the fundamentals -- or everything falls apart. When we begin shooting, we have to stand still and shoot at a target that doesn't move, so that we can BE steady in a dynamic situation.
However - after mastering the fundamentals, PLEASE don't stagnate! Once past the beginner phase, going to the indoor range and standing still in the stall, and shooting at the colorful paper zombie target that doesn't move, may hold you back from advancing as you could. Try out new positions and stances, multiple targets, shooting with the weak hand, reloading with one hand, clearing malfunctions, etc etc etc (as much as can be done while observing the range's safety rules!)
As you progress, add movement. There's a way to integrate dry fire and yes even airsoft into learning the body mechanics. (integrate, as in practice with and without live rounds). Just don't fool yourself into thinking that a recoil-less dry fire training session represents live fire, so do both live fire as well as dry fire. Follow up shots are entirely different in dry vs live, of course. A great benefit lost on many detractors of dry fire is the bodily stress you'll work up during those moving&shooting sessions. Your heart will start to race, your adrenaline will start to flow... (yeah! kind of like in a fight!) You'll learn/remember to breathe (too many people hold their breath during a fight of any kind!)... so, call it "aerobics for combat"? Being accurate and focused to move and shoot, while your heart rate exceeds 160bpm, is a whole new ballgame. I work it in with my at-home workouts, so I figure it just helps me lose a couple pounds of turkey, ham, stuffing, and potatoes that I've gained the last few weeks

Whatever your skill level, commit to doing a few sessions of practice each week by dry fire, AND also going to the range at least once a month and shoot a couple boxes. Bring a buddy to watch your form and technique; it not only helps you find where you can improve, but it keeps you committed to the training AND makes it a lot more fun.