[Viking]

I think the pros and cons of kneeling can be explained in better context.

When in a close quarter urban environment, there are places that kneeling, as Gato eluded to, will likely get you shot quicker than if you were standing. I would be the first to agree.There are other places in that same environment that kneeling has advantages over standing.

If you are moving in a small group during a "low signature" movement inside a structure, taking a hallway corner can have advantages when taking it on a knee. Typically we anticipate movement at eye level, and sometimes a threat breaking cover from a low position can take us by surprise. The knee also allows a partner to pick up a position directly over top, so essentially you end up with two guns taking the corner simultaneously, as Shelled Pants mentioned in his post. This is also a current practice in some military and LE units, which has proven to be very successful.

When you lose the element of stealth and things are getting loud, the knee is even being practiced by some units in order to take a corner aggressively. I've already mentioned that breaking cover from a low point is not always anticipated. Now take into account that action is faster than reaction. By taking a corner aggressively, it causes a threat to react, which gives the person taking the corner the advantage. Sure, there's other factors involved that could deny the tactic, like an awaiting, defended and prepared position. If there was a 100% fail-proof tactic out there, everyone would be doing it. Unfortunately there isn't. We don't have chances until we take chances. That's fact.

As far as room clearing goes, kneeling can be used when you're once again moving quietly through a structure and need to slice the pie on a doorway. Some units drill this in a CQB environment, and will do this in tandem like I described how corners can be dealt with in hallways. The fatal funnel works both ways, guys. If you can slice the pie effectively on a door and come across a threat before he or she can react to you, you have an advantage. If you're 5 minutes into a gunfight, sneaking to the door may not be your best option. That scenario could potentially become an explosive, dynamic entry...if you even need to enter. Again, it's all in the right context. Is there a place for kneeling? Absolutely. Is it 100% effective all the time? Nothing is.

UK folks used to have an IA of taking a knee and transitioning to handgun on a primary stoppage in CQB. That's not a practice anymore. Kneeling inside a room has been replaced with lateral movement. Keeps guys mobile and in the fight. Their US counterparts are similar, but will still employ the knee on taking corners on longer angles, on occasion. Not a suitable technique for inside tight enclosures, but it's a technique in their repertoire nonetheless.

Most of this discussion is based on reactionary gaps. Time and distance equals a reactionary gap. In terms of shooting, distance and cover can permit you to kneel and/or plant to make sighted shots. Yet as we decrease our distance to threats, we decrease our reactionary time, and unfortunately improve our threats accuracy at the same time! So we have to know what is an acceptable sight picture at any given range. I believe an understanding and appropriate use of tactics also falls into this responsibility.

One last note on that picture above. I can't stand armchair generals, so I'll make some broad assumptions here.

Hugging cover is a cardinal sin. Rounds that don't impact you and hit your cover will tend to travel the plane of that cover and still tag you. Both horizontal and vertical cover. BBs can resemble a similar behavior at times. Bullets impacting cover can also generate spalling and debris, which can be equally deadly to you. Fighting off of cover minimizes the chances of ricochet. All that being said, if you take a corner and have time and distance and some advantage in your position, there's nothing wrong with taking up a supported position to make a sighted shot.