## Wednesday, June 22, 2016

### Seeing vs Calculation

From the 80 puzzles I have studied, there is a certain amount of which I have difficulty to SEE the actual solution. I can calculate the solution, of course, but I have the feeling that it should be possible to see it. But somehow, my mind is protesting against that.

The other puzzles I have studied change from complex to simple, once I found the solution and investigated that. Once a solution has become simple, I can see it. No calculation is required any more. It is clear. But the positions I'm talking about now, remain somewhat cloaked, even after the solution is investigated and has become well known. I am not able to see the entire solution, but I must still calculate parts of the solution.

So far, I haven't found the common factor in these positions. I hope you can help me to find that:

Diagram 1
Diagram 2
Diagram 3
Diagram 4
Diagram 5
Diagram 6
Diagram 7

Only 7 out of 80 isn't too bad, of course, but I have the idea that I can learn something specific and important from these positions. Something that would help me in future positions. A way of seeing without the necessity to calculate.

 Abacalculusator

1. Every time I click on the diagram links I get a different puzzle. So it's impossible to assess the problems you had difficulty with.

(Not that I'm likely to be able to help, but I thought I'd at least look at them.)

2. That is strange. Are there more people that have the same problem? You can see the puzzle number in the link. Even when I'm logged out from CT, it links to the right problem.

3. Hmmm, I seem to be getting the same problems now, but was getting different ones from my phone. I'll try again later this afternoon.

4. I don't encounter the behavior Todd Durham describes. --mfardal

5. I didn't have any problem linking to the individual problems. I did notice that as soon as I "completed" each problem, CT went to the next one (which is normal CT behavior). Perhaps this is what is happening?

I'm still thinking about how to describe the "common factor" (if there is one) shared among those 6 problems. It certainly "feels" like there is a commonality, but I'm not sure (yet) what it is exactly. Perhaps I am "seeing" an illusion of commonality because that was the instructions. . . Those "invisible gorillas" are hard to detect!

6. Diagram 1:
I see no moves for the Qh4 and the Bg2
The Nd4 AND Nc5 are attacked 2 and defended only 1.
BUT there is the x-ray Rd1 - Qd8
1. BxN NxN is doing nothing but: to enable the discovered attack Bxg7 gardez! which forces black to defend their queen instead to retake the bishop. A sequence of takes where you take first and last is usually benefitting

7. Diagram 2
Without the Be5 its a mate in 2
So its about an x-ray attack again ( Bb2 - Kh8 )

8. Diagram 3
This is a combination of weaknesses and a matter of the right move order
Bc3 attacked 2 defended 2
Qd3 and Re2 are attackable (x-ray attackable/skewer) by Ba6
So the first move is doing nothing but to prepare the tactic. The Queen gets overworked to do something against the Bh6 and to protect the Rc3

9. Diagram 4 is tricky in my eyes, i suspect it is solved for the wrong reasons
White is up in material

The logical line seems to be 1...Rxc2 now White is down an exchange and needs to take Bxf8 but now exNf3 with a threat of a discovered attack Re2+ which wins a piece
But white has a better defence: 2.Nd4.. i did not see this move
White is only down an exchange and will get it back because of a double attack on both rooks

10. Diagram 5
The Bc8 is (x-ray) attacked 2 and defended 1
There is a N-e7+ opening the line Rc2-c8 further
So again..
1.Bf6 does nothing but to increase the x-ray weakness c2-c8 and the Nd7 gets weak ( 1-1 )
Now Na7 is attacking the defender of Nd7 twice

2...Nc5 is creating a Tit for Tat, now its important to have more takes in the pipeline to be the first and last to take
Nxc8 with the threat Nxd6 so Rxc8 to reduce the pipeline of white takes
The material balance is equal
And now we use the Tit for Tat : I take your rook and you take my Knight and im up an exchange

11. Diagram 6
Weaknesses of white
The king is exposed to many checks, Ng5 is simply hanging
The rook at d2 is (1-1), Nc3 is (0-0) but i cant see any chanche to make use of this

So its a Tit for tat: If we make use of the weakness Ng5 white uses the weakness along the d file.
To remove the wreakness with check is method no 1 in such situations
Again you try to keep many takes in your pipeline. And reduce takes of yourr opponent

12. Diagram 7
Weaknesses e7-h4,Nc3,N-e3+/fork and Qb7-g2 but i cant see how to use this one.
The weaknesses forces you to think about the discouvered double attack 1...Nd5
But the knight can be pinned by a queenmove which helps against both threats and here the tactic starts now e3 is weaker and ww try to keep the pipeline full...

Diagram 7: (02:43)

Quite hard task, but if you see it closely it is not that hard.

The WQueen has only one safe square. The WKnight at c3 is not defended. The BBishop is attacking the Q via the X-ray.

Let's merge two ideas into one. 1...Nd5! and both objects (Qa4 and Nc3) are attacked. Now the Queen has to defend the N and has to go to d5. What now? We can see both Queens stays opposite. Moreover WQueen pinned the Black one! You cannot play Nxc3 as you will lose the Q. But what if we look for another duplo attack? We can play Nde3+! to discover the attack as fork to K+R. After the forced sequence 2.Qe4 Nde3+ 3.Bxe3 we have to exchange the Queens... and win the exchange! 3...Qxe4 4.fxe4 Nxe3+ 5.Kf3 Nxd1 Nfxd1.

Diagram 6: (01:01)

Not that hard if you spot simple discovered attack.

If you play BxN white will play RxN and there are the same (equal) exchanges. Therefore you have to find something else. What is it? Open the attack with the N as after the R will take it (Rxe1??) you can take his R with check (Rxd2+). After King goes to f1 we can play RxR and the Rook has to go to d2 - and we take the N at g5 together with attacking the R! And white cannot take BOTH pieces with one move! (Ne1 and Bg5) After the best move KxN and BxR+ KxB Black wins the exchange.

Diagram 5: (03:37)

This one was really hard to me. It is because there were too many motifs and possible solutions (variations). How did I came up with the correct solution?

The last Black's move was Kg6. The King get off the pin. What would it be If I took the "unpinned" Knight? There are two variations: Black King can take it or N can take it (on f6 square).

I immediately saw the winning sequence after NxB: BxB and if RxB Ne7+ Bxe7 and RxR. It was very easy to me to notice!

But what would it be if the K could take it? Let's see! KxB and now I cannot play BxN because after BxB Nb6 the Bishop simply takes another Knight (BxN RxB) and the position is equal. But if the Black WSB would not have defended the N... I could take it with my Bishop! Ok, let's exchange (capture) the defender (Bc8) of Black Knight! I played Na7 and it is duplo attack and Bc8 cannot move as it will not defend its N! Therefore... 2...Nc5 3.Nxc8 Rxc8 4.Bxc8 Nxa4 winning.

Diagram 4 (00:32)

This one was very easy! There are only two variations (candidate moves) to consider: RxQ or pxN. If I play RxQ white will answer Ne5 and there will be triplo attack (KxR, BxR and NxB). It will not give White a decisive advantage. But when I play pxN! I realize two goals: gain (capture) the N and attack Queen for the second time! And if he answers back with BxN I can play RxQ! and there is a discovered attack behind the door and White B is under attack as well. There is no defence against both of these threats (Re5 -> Rc5+ RxB RxR and if White runs away with the B White will plat fxg2 making new Q with the next move).

That's why the best scenario is simple: 1.Qxc2 exf3 2.Qxf5 Rxf5 winning

....

14. ...

Diagram 3 (01:08)

I failed to solve this puzzle correctly, but it was due to my lack of patience. If I would be forced to solve it - I could finally find the best variation.

If you look very closely - it is more than visible - the Q and R stand on the same white square diagonal! and after Ba6 you can exploit this feature. Of course not as the first move, but maybe the next one...?

1.Bxc3 --> now the Bc3 is attacked and defended twice. What would it be if I exchange at c3? Let's see. 1...Bxc3 2.Rxc3 (Queen cannot take as the piece at c3 is attacked) and now let's exploit the Bishop power! 2...Ba6 3.Qxa6 (or Qc2 RxR QxR and now BxR BxB with the same final) 3...Rxc3 with the advantage.

Diagram 2 (00:30)

I think this position is an easy one. It is mainly because I analysed a few examples with two bishops pointing out at the enemy King with the support of the pawn.

0...Bxd5 -> the R is attacked and if you play Bxe5+ Black responds with Nxe5 and after RxN RxR RxR Bxp Rxp Bxp and the position is equal. Therefore we have to take with the R!

1.Rxe5 Nxe5 2.Rxe5 Rb8 (after RxR BxR+ Kg8 h7 is mate - now you have to know {be familiar with} very important mate pattern!) 3.RxB+ RxB+ KxR winning.

Diagram 1 (01:52)

I failed to solve this puzzle due to the laziness and lack of patience (it was not that easy as I predicted). I knew something must have been done with Rd1 and Qd8 (the same file) and my focus was attracted by Nc6. Anyway I played Rxd4? and spoiled the solution. The correct solution is quite a nice one (at least to me!) because after 0...Nxd4 1.BxN NxN 2.BxB Qc8 there goes Qh6 or Bg7 escape to the safe square.

Definitely this position was too difficult to me to solve it without "sitting on my hands" ;) :).

Let me know if such a description helps and what else can I (we) do to give you more support with these positions! Thanks a lot for giving us the real examples!

15. In all 7 positions, there is an initial blunder that sets up the potential for successful tactics: failing to see all of the potential direct and indirect threats that are latent in the problems. The geometrical motif (in particular, involving empty squares and line moving pieces) is dominant, with other themes present (B.A.D. pieces; Loose Pieces Drop Off, discovered attacks, forks, pins, etc.). Counting (NOT in the sense of counting relative material, but in counting the ratio of attackers and defenders on specific squares) is also dominant. If the appropriate counting is done, it simplifies the calculation process considerably (IMHO).

My summary of the commonality: Combination of direct (immediate) and indirect (eventual) threats to maintain material advantage. Only position 2 has a potential mate threat or Pawn promotion, but the key is still material advantage.

My two cents worth. . .

16. Thanks all for reactions! Your comments give me an idea where the trouble stems from. The common factor in all positions seems to be the mutual exchange of pieces. The following decisions have to be made: which hostile pieces must I trade, which attacker must I use when there are more attackers for one target, which trade must be the first, which counter trades must I look at, what is the net result of a series of exchanges?

Apparently, positions with multiple mutual exchanges are taxing for my STM. And when a memory overload becomes manifest, I loose the vultures overview, and I cannot get it back by only willing it. But when I look longer at the positions, slowly the mist clears, and after half an hour or more, it disappears. Thus proving it is possible to see these positions as simple too.

Besides pondering about these positions for a long time, I must try to distil a few rules that prune the possibilities. A piece trade model, so to speak. I will have a closer look at your comments for inspiration later.

17. This is a great conversation. I didn't look at the positions enough to contribute to the discussion, but I enjoy reading everyone's comments and looking forward to getting into them a little more.