My take on stances. I apologize for the length.
Suarez International, Inc. http://www.suarezinternational.com
"Do not think that I came to bring peace on earth. I did not come to bring peace but a sword".
The shooting stance you use is irrelevant as long as it provides you with certain, combat-essential attributes. I am well aware that there are a multitude of accomplished competitive shooters who favor the Isosceles Stance, and think Weaver shooters are a bunch of throw-backs. An equal number of accomplished Weaver shooters believe anyone shooting from an Isosceles is a dope-smoking pinko infidel.
Some of the loudest proponents of each "system" are very talented individuals that can probably shoot better in a competition or a shooting school, with a single hand, and their eyes closed, than the majority of shooters using two hands. Both of these two prolific environments, however, are a far cry from the reality of personal combat that they seek to emulate.
For many years I was a firm and exclusive proponent of the Weaver Stance. Heck, I was a product of the Arizona Vatican. I still favor and use a Weaver-like posture because it fits my body-type. But, I have also seen and trained with many shooters who are just as good firing from other positions. I've come to the conclusion that whatever posture you use, or whatever you call it is not as important as making sure that it allows you to do the following things.
It must allow mobility, it must provide good balance, be aggressive in configuration and cultivate aggressiveness in the individual using the posture, it must be suitable for transitioning between hands to guns and vise versa. It must work with all firearms, not just pistols. It must be suitable as a hand-to-hand combat posture, not just a shooting stance.
A firing stance is a fighting stance. I'm trying to get away from the word "stance" because it denotes "standing" instead of "moving". Let's use the word "posture" instead. Now, let me preface this by saying that I could not care less, from a combative perspective, how fast, accurate, or doctrinally-correct (Hey, a new term!) you are in a competition or at some shooting school. Whether an Isoceles or a Weaver works better in a pistol match or at the "final exam" of some shooting range is irrelevant. It doesn't really matter to me what they do in these controlled environments (no body ever died from losing a pistol match). I'm thinking exclusively about using whatever weapon is involved to fight against someone at extremely close range.
Many gunfights begin by surprise, at close range, as physical assaults. Often, you don't know initially that its an actual "gunfight". Also, you may be in a physical confrontation that doesn't call for shooting, so your "stance" must be suitable for defending yourself physically as well as ballistically.
Here's a way to look at it. If you were going to search your house armed with a knife instead of the pistol, how would your posture look? If you knew that the guy you are holding at the "ready" would charge and try to tackle you, how would your weight be distributed? If you knew you were about to receive a haymaker in the face from an oversized steroid abusing hoodlum, how would you stand, how would your posture be? When you answer these questions, just put a pistol into the package and you have the ideal shooting "posture".
You'd have a slightly bladed posture, well-balanced, aggressive in appearance, braced for collision, with your knees slightly bent, and in a manner that you could move quickly to any point on a 360. That doesn't sound like a traditional Weaver or an Isosceles, or any other marksmanship-oriented stance to me. It is certainly not a "plant-your-feet-face-downrange-and-make-ready" stance.
To the group that thinks "they carry a gun so they don't have to worry about all that combatives stuff", let me sober you up. Can you legally shoot the guy who tries to punch you in the nose? What about the guy who grabs your shirt, 'cause you accidentally glanced at his date's skimpy dress? Fighting happens on many levels and requires an understanding of the dynamics involved, and the rules of engagement you operate under. Shooting is not always the answer, and it may not be the answer initially, even if shooting is required as the fight develops.
Your lower body must provide a solid and stable platform from the waist up from which to fire the shots (or punch, or cut, or whatever). How the feet are positioned is really not very important. The posture must give you good balance. If you fall down, you may not get up. The posture must also allow you to move, because when someone is trying to kill you, and you are trying to do the same to them, you WILL move, or you WILL die. You must have balance, and you must be able to maintain an aggressive posture. Who cares what you call it as long as you can be aggressive, balanced, and stable from the waist up.
"But wait, Batman", you yell out a protest. "What about recoil control, the 'experts' say I MUST use a Weaver or my pistol will fly out of my hands".
Take it easy Grasshopper. Your upper body mass and weight is what contributes most to the management of recoil, NOT the positioning of the arms. That's why modern competition shooters use the Iso, because they rely on the upper body's mass, and not a tenous tension in the arms to control the movement of the pistol. Even a malnourished Pee Wee Herman has enough upper body mass to control a 1911. Its just not as big a deal as we were originally told.
Now in my photos, you notice that my upper body approximates a Weaver, with the bent support arm, and all that. I hold my upper body that way for uniformity training between pistols, SMGs, Rifles, shotguns, etc., not to control recoil. It is also a better fighting posture.
Let's discuss the overall aggressiveness of the posture. Aggressive, by the way, is specifically what you want in a shooting/fighting posture. When the mass of the firearm is above both arms, in what direction will the weapon move when it recoils? That's right, straight UP! When you remember that it is desirable to always shoot a single assailant twice (sometimes, you must him twice…a number of times!!), this means that you will have some recovery time between shots. The speed with which those two shots are placed in the adversary is of critical importance, because we are racing his nervous system to shutdown. This is paramount to incapacitation.
While aggressiveness in a stance is important, don't go too far here. You cannot eliminate the weapon's recoil by leaning forward so far that your rear end sticks out like a candidate for a police promotional exam. Also, you should specifically avoid the straight up erect stance (the "tall in the saddle" stance) and the backward leaning stance of the bulls eye competitive shooter.
Again, please remember that the intent here is not learning to shoot in the controlled environment of the firing range to win a shooting medal, or some guru's signature on a piece of paper. These are fine pursuits for those whose interest lies in that area, but it is not the focus of this study.
"But what about the weapon tracking in a uniform and balanced manner like it does in the Isosceles", some IPSC guy yells out from the other side of the house.
"Tracking?" Who cares. Just hold the pistol on target and hit it as many times as you need to until he falls down and stops what he's doing. Uniformity of tracking is a hair that doesn't need to be split. Is this an issue at a high-speed leather Stel Challenge event? Maybe, but I can assure you that it will never cross your mind in a gunfight.
Stand slightly bladed to the target, at about a 30 degree angle (more or less, we don't need a protractor here!), with the support side foot leading by about half a step. Traditional isosceles shooters will notice that standing straight on to the target with feet side-by-side is de-emphasized in favor of a slightly bladed, one-foot forward, attitude. There are various tactical, martial, and physiological reasons for selecting a bladed posture instead of straight-on posture: We have greater balance for violent quick movements with one foot leading the other. We are braced for collision if it suddenly turns into a contact fight. We are able to keep the weapon protected (using a CQB posture) from an adversary. And finally, if we need to strike him with the firearm, we can generate more force impact this way.
Do not exaggerate the 30 degree angle. Turning too much will create tension in the shoulder area, which in turn will cause lateral stringing of your shots, as well as rob you of physical power if you have to smash someone with your fist or pistol.
Keep the feet, the knees, the hips, and the shoulders in line, without any twisting of the torso. Holding the pistol in a two-handed grip, extend it out toward the target. Keep the firing arm relatively straight, although it need not be "locked". If you want, bend the support side arm slightly as well, for uniformity of weapons training, and to keep the weapon closer to the body, although you don't absolutely need to. This is far removed from the two locked arms of the traditional Isosceles, the squared-on but relaxed Modern Isosceles, or the rigid Weaver, but it is a vast improvement for our purposes (ever try to fire an SMG from Isoceles?).
For those who prefer a strict Weaver oriented stance, forget about that silliness of pushing out with the "strong arm" and pulling back with the "weak arm". Just bend the support side elbow in a manner that the elbow is pointing downward toward the deck. This in turn will place the upper limbs in a position to create a slight isometric pressure, which will not only aid in getting indexed on target, but it will also reduce muzzle flip even more. Notice that the isometric pressure is not an intentional tensing of the muscles. You do not intentionally "push and pull". It occurs naturally because of the configuration of the arms. Do not think "push-pull", rather simply get into a proper posture. Everything else will take care of itself.
Pistol shooting, like any other martial art, is evolving. Part of that evolution is the realization that shooting is only one facet of the entire focus. The overall focus is on fighting, and integrating all the force options. When that is accepted, the issue of whether you fit into one type of classic stance or the other loses the importance it once had. The question now becomes, which posture is best suited to my needs. As long as your mission parameters are met, and you get the best results you can (you win the fight), who cares how you stand..