I explored the tactical themes from So-Nakamura, Saint Louis 2015 in my blog post.
I felt it very important to highlight three strategic themes that result in the tactical fireworks working.
Strategic Theme 1: Prevent Nc7 and thus slow down White's Queenside play
The million dollar question when I play the Black side of the King's Indian is whether I should continue pressing on the Kingside or attempt to slow White down on the Queenside.
This is an example where if Black plays ... g4 (which I believe Bacrot has continue) he is going to run into Qc2 with Nc7-e6 to follow.
Observe how Black spends to moves in restricting the Knight's activity via ... a6 and ... b5.
Whilst he weakens c6, the actual occupation of that square gives White nothing concrete.
Strategic Theme 2: The ... h4-h3 pawn advance threat
Whilst I'm familiar with ... g3 and ... Bxg3 ideas, this is another pawn storm idea for me to store away.
Black leads with ... h4 intending ... h3 to shatter open the White castled position.
Pay attention to the follow up ... f3 break, with the entire idea of Black invading along the f-file with ... Nxe4
Strategic Theme 3: The Qf8 setup
In the diagram from Theme 2, it's worth noting to myself the roles of each of Black's pieces
* The Rook on f7 guarding the 7th rank (previously preventing Nc7). He may swing to g7 and he also allowed ... Bf8 securing d6.
* The Queen on f8 defending d6 but also carrying threats along the f-file.
* The Bishop on d7 guarding c6 and c8 and acting almost as a keeper of the wall.
* The Bishop on h6 threatening to open up the h6-c1 diagonal and invade at e3 (not so much to win the Rook).