## Sunday, July 10, 2016

### Two tempi gain wood

I have selected a problem set where the first move is a capture. The second C of CCT. Categorizing them and investigating them is an ongoing task, rather technical, so there is not much to write about. But from time to time, a little nugget is unearthed. We already know that a duple attack gains wood by the effect that two targets are attacked with one move, while the opponent cannot save two targets with one move (usually). The same principle works with captures. If you can gain two tempi with one move, it gains wood (usually). Unless your opponent has a duple tempo move as an answer. See the following diagram.

 White to move
r2qr1k1/ppp2ppp/2nb4/8/3PB1b1/2P1BN1P/P4PP1/R2Q1RK1 w - - 1 1
Solution

As you see, both a white and a black bishop are hanging. Taking the black bishop is just a trading off of the bishops. But 1.Bxc6 gains two tempi. It attacks the black rook, and it prevents the bishop from being taken on e4. So even one tempo is a defensive one! The move trades off a problem piece of white with tempo. It is important to develop a sense for those two tempo moves. Both offensive and defensive.

1. I would expand this great move!

1. Bxc6 and its purposes:
a) it escapes from capture
b) it captures the piece of equal value (Nc6)
c) it defends (!) the attacked piece (Nf3)
d) it attacks another piece of bigger value (Re8)
e) it attacks not defended pawn (b7)
f) it goes at the attacked square c6 - by the b7 pawn

And now the position is as follows:
1. pawn attacks Bh3 (the threat is to capture it for free), the Bishop is hanging
2. bishop attacks Re8 (the threat is to capture it and wins the exchange)
3. Bishop attacks b7 pawn (the threat is to capture it for free)

I love such moves: to me they are identical to "desperado effect". It is the same as Nizmo showed at his classic book My system: "we play the move Bxc4 (after d5xc4) and develop the piece, retake the pawn and make castling possible" (my paraphraze).

And yeah - I would call this move "two-purpose" - defensive-attacking one!

2. OFF-TOPIC:

My present research with simple tactical puzzles has already shown there are a few really things important to understand (and take into consideration when analyzing/solving much more difficult ones).

1. You have to be able to correctly EVALUATE the final positions - otherwise some variations you can think of "winning" and they may be just "equal" (dynamically).
2. Most puzzles require using duplo attack to win material. In broader sense and more difficult positions - it is duplo threat.
3. The better you can recognize patterns and motifs, the faster you can (correctly) analyse hidden resources.
4. If can see all the attacked pieces and squares from both sides, finding the correct solution may be a bit simpler.

Let me know if you have already analysed these points above and which ones are critical ones or just of a small importance. I will be testing more of the puzzles and share my conclusions with you!

1. Ad 1. At the moment I'm only interested in the mechanisms that gain wood. That goes beyond the position, so evaluation of the position is not on my priority list AT THE MOMENT.
Ad 2. Understanding the mechanisms that gain wood is key. Single checks and threats just POSTPONE the obligations you have. Only a capture cashes in. Usually at the cost of a tempo. It is not so easy to become tempo-aware. Yet I belief it is paramount.
Ad 3. True. Study is about discovering new (virtual) patterns that are now hidden.
Ad 4. I doubt that that is the problem. The problem is to see the functions of the pieces. What do they DO?

3. I found the following position in Yuri Averbakh's Chess Tactics for Advanced Players, diagram 67, page 43. It is from the game Hohler, Peter - Tcherniak, Gilles - Wch U20 prel-C (6), Muenchenstein/Basel, 1959 (but listed in Averbakh's book as from Heidenheim); E91-King's Indian.

Black's last move was 20. ... Na6. WHAT SHOULD WHITE "SEE"?!?

No potential attack on either King, and no possibility of Pawn promotion; therefore the position is (potentially) about material gain.

Hohler - Tcherniak

[FEN: r3r1k1/2qb1pbp/n1p2np1/4p1B1/1P2P3/P1N2N2/2Q1BPPP/3R1RK1 w - - 0 21]

What a rich set of tactical (capturing) possibilities! And yet, after a few quick glances and COUNTING, it becomes fairly easy to "see" the correct moves for White.

I note the following piece/square interactions as I "saw" them:

On a6: White attacks (Be2); Black defends (Ra8) - balanced (B.A.D. piece potentially)

On f6: White attacks (Bg5); Black defends (Bg7) - balanced (B.A.D. piece potentially)

On e5: White attacks (Nf3); Black defends (Qc7; Re8) - Black controls e5 - discontinue any further consideration because White cannot get at e5 very easily with more pieces

On c7: White "attacks" (Qc2; possible Knight attack IFF Nc3 moves to take advantage of the potential pin on Pc6 [except for that Nf6 defending d5] - SIGNIFICANT INTEREST!); Black defends (Na6) - balanced (B.A.D. piece potentially) (IMPORTANT CLUE!)

On d7: White attacks (Rd1); Black defends (Nf6, Qc7) - apparently adequate, but B.A.D. piece potentially IFF the Black Nf6 is eliminated and the Black Queen is forced to move away from the defense.

21. Bxa6 (Eliminates one defender of the Qc7) Rxa6 (Forced recapture) 22. Bxf6 (Eliminates a defender of d7) Bxf6 (Forced recapture) and now a "stepping stone" position and assessment. The Qc7 is now UNDEFENDED! The Bf6 is now UNDEFENDED! [The Bd7 is now a B.A.D. piece!] There is now a Knight fork on d5 which attacks both "loose" (undefended) pieces - Qc7 and Bf6!

23. Nd5 1-0

After 23. ... Qd8 (Qd6) the "count" is now one defender of Bf6 and one defender of Bd7 - the Black Queen, which is now overloaded with defensive functions. After 24. Nxf6+ Qxf6 25. Rxd7 snares the (now undefended) Black Bishop, winning.

All that writing masks how simple and fast it was to "see" those interactions and "count" the various piece contacts. When I "saw" the position, it took less than 10 seconds to "see" the "solution" via counting. Yes, there are some subliminal things going on concurrently, most notably various motifs, but the subconscious "threw up" the lines of play almost as fast as my eyes moved across the board from left to right, just noting and counting the various interactions.

Food for thought, perhaps. . .

4. typical tit for tat position, if i "tit" then you "tat" and the standard method is to remove "tat" with tempo. You create a double attack