A lot of players think the K-Indian Attack is easy to play because they believe you can, as White, simply play the same opening moves against anything Black plays and so avoid opening study. No matter how many times I tell them this is NOT correct I get ignored.
The fact is the King’s Indian Attack is a very complex opening. As White, you must adopt a different strategy for each possible Black formation. Black has at his disposal, among other things, setups resembling the Sicilian, French, K-Indian, Gruenfeld etc. and against each one White must play a different strategy. This means it requires just as much knowledge to play correctly as say the Ruy Lopez or Sicilian. There is no “one-size fits all” opening.
This game also illustrates another point. I have a 1.3 million game database I refer to for openings. A recent check showed that against opponents rated over 2200 we usually leave the database around moves 11-12 while against lower rated players, it’s around moves 6-8. So…even having all those games available for reference is pretty much useless if you don’t gave a grasp of the IDEAS behind the openings and are unable to grasp the strategy that dictates the how a given position should be played. That makes the study of strategy at least as important as tactics.
In this game Black left the database at move 8, but it seems his move was no better or worse than other moves.