Study Method
When studying the KIA, you don't study lines, you study plans and middlegame ideas against Black's possible formations. Before we start, you have to realize that the KIA is not actually an opening. In fact it has a total lack of any opening play. The KIA is just a bridge that allows you to avoid the violent waves of the always stormy "opening ocean" and moves you quickly and safely to the "middlegame valley". Although this may sound good, it's also bad because it means that you need better and more detailed preparation to achieve good results. Just as your opponent can't surprise you, you also can't surprise him so the battle transfers directly into the middlegame where understanding has the main role. Practically, as I already said, there is no opening, so no one is fighting for an opening advantage. The KIA is an "understanding contest" right from the first move.
(This forum topic series was originally posted in April, 2012 by Michael-G in another group. I only edited it for minor spelling and grammatical issues and changed the original topic names to keep them listed together here at KIA inc. Italics were added for editing or emphasis.
I have read close to everything there is in print, on the web, and in other media about the King's Indian Attack. None of it was as revealing as the following information was. Please enjoy. - Editor.)
INTRODUCTION TO THE KING'S INDIAN ATTACK
The King's Indian Attack (KIA) began to show up in the repertoire of masters around 1950. This was due mainly to the successes reached by players of the black pieces in the King's Indian Defense (KID). As often happens with openings or lines named "Attack", the King's Indian Attack is not actually an attack. It can be an attack, but it can also be a very positional opening. It was named "Attack" because of the unusually good results it had in the early years of its appearance.
The great advantage of the KIA is that it has a standard development formation that White follows no matter what Black plays. White has an answer against all the major 1.e4 defenses. That allows him to sit down at the board without having to worry about what Black might play. For OTB games that means extra time on the clock and a "ready-made" understanding of the positional and tactical nuances. While time-limit constraints may prevent opponents from coming to grips with these same nuances.
For the KIA player, the advantages don't stop here. Black, no matter what he does, can't surprise a well prepared KIA player. There are no possible novelties, surprise moves, or traps. If, as White, something does surprise you, it's either bad and you are going to have a good game, or you didn't study the KIA correctly. The KIA has been analyzed in detail and carefully studying the following illustrative games will give you a definite advantage against someone that hasn't studied it properly.
One more advantage is that it is an almost forgotten system nowadays. Most don't even bother to prepare against it and, even if they do, they will rarely have the same familiarization with it as a dedicated KIA player.