Mid September 2015 highlighted a number of holes in my tactics and calculation.
I've recorded my attempts at Blokh's Combinational Motives, made a note of which ones I got incorrect and have attempted to improve my understanding of the positions.
It's becoming apparent to me that I opt for brute force sacrifices. The more difficult tactics require some subtlety using deflections, interference, creating a secondary weakness.
Diagram 851: Difficulty 3, White to Move
I had chosen 1. Ng5 hg 2. Qh5. However, Black is not obliged to cooperate with me and I missed 1. ... f5
This tactic works because of the weakness of f7.
White has 5 attacking pieces in reserve: Ba3 cutting to f5, Knight pouncing at g5, Bd3 shooting to f7, Rf1 aiming at f7 and the h4 pawn opening the h-file in some lines.
Black's pieces are not coordinate in defence.
Diagram 854: Difficulty 4, Black to Move
I had looked at ways of trying to capture the Knight at g3 taking advantage of the pin on f2.
I had missed the ... Rf3 idea, remarkably similar to Diagram 851 where a Knight also moved to uncover a Rook threat.
I had chosen ... b5 which isn't as forcing.
This tactic works due to the power of Black's Bishops. A pin at f2 and a strong point at f3 where the Bc6 and Rf8 intersect.
Black's pieces are far more active than White
Diagram 858: Difficulty 6, White to Move
This tactic has hidden depth, in that ultimately one is trying to deflect the Bishop f8 from defence of h6.
I had chosen Bxh6, attempting brute force that doesn't lead anywhere. More so I made a mistake of not listing candidate moves.
I had missed the idea that should the h-file open, White has Ng6 exploiting the pin at f7.
White really activates all pieces with Rad1, Re1-e3-g3 ideas.
Very cute is this Qf6 move threatening Ng6+ and Qh8 to follow.
Diagram 863: Difficulty 5, White to Move
I did not find the candidate move idea, as I was fixated with brute force ideas to sacrifice at h6.
I'm learning that up to a point, these positions are defended too well to be cracked by brute force and require some subtlely.
Subtlely comes in the form of deflection, interference and decoy.
The stratetical and tactically fight revolves around g6. Once this can be blocked/interfered by White, the sacrifice at h6 is devastating and winning.
Diagram 864: Difficulty 5, White to Move
Another example where I took the brute force approach of Rxd7. One needs subtlety to first create the weakness (shattered Kingside) after which one can remove guards with brute force.
Memorable are two ideas.
1) Ideas of Rxf6 to leave the Bishop on b2 to threaten the discovered check.
2) Qg4+ which either allows Bishop and Rook to coordinate at h8 or pushes the King to f8 allows Ba3 and Rh8 mate.