Basic positions

Here below are some positions that I consider to be basic, in the sense that they should be well-known by any tournament player. They are not necessarily easy.

Pawns against pawns

One of the things I want to do in life is to study the following position. White to move.

Position 1

It's a position I thought of, although it's possible it has been examined before.

[Edit: I found out that it's in fact a study of Tattersall 1916, he says white wins and gives the following line. 1.b4! (1.a4? a5 2.d4 (2.c3 c6) 2...d5) (1.a3? b5 2.b4 (2.d4 d5) 2...d6) 1...d5 (1...b5 2.d3 d6 3.c4 bxc4 (3...a6 4.c5) 4.dxc4 c6 5.a4 d5 6.b5) (1...c6 2.c4) 2.b5 d4 3.a4 c5 (3...a5 4.bxa6 bxa6 5.a5 c5 6.d3) 4.bxc6 bxc6 5.a5 c5 6.c4 dxc3 7.dxc3 c4 8.a6 1-0]

It's clear that any king move loses immediately, and this is true for both colors.  Therefore all the action happens on the queenside.

I think I have not yet figured out everything but just to explain the difficulties let me set up a much easier position.

Position 2

Here I think white wins with 1.a4! or 1.d4! They are both good by the symmetry of the position. Instead, 1.b4 and 1.c4 lose. Before looking at the winning lines let's see why 1.b4 loses. We have 1.b4? b5! 2.c4 c5! 3.bxc5 dxc5 4.cxb5 axb5. There are no tricky pawn breaks in this line because here things are pretty simple: in a promotion race the more advanced pawn simply wins.

White needs to put black in Zugzwang.

Let's examine 1.a4. Black has four possible replies.

a) 1...a5 2.b4. Now 2...b5 loses because white will promote first, 2...c5 loses to 3.bxa5 bxa5 4.c4, and 2...d5 loses to 3.bxa5 bxa5 4.d4.

b) 1...b5 2.axb5 axb5 (2...cxb5 3.b4 d5 4.d4) 3.d4 c5 4.d5! c4 4.b4.

c) 1...c5 2.b4 b5 (2...d5 3.bxc5 bxc5 4.a5) 3.a5 c4 4.dxc4 bxc4 5.b5.

d) 1...d5 2.b4 c5 3.bxc5 bxc5 4.a5 c4 5.d4.

I want to show another "simple" position to try to understand the problem better.

Position 3

Here white has the move, and I believe this is a win for black. The strategy of black is to reply to the moves with central symmetry, meaning for example that to 1.a3 he should reply with 1...c6 (axial symmetry would be 1...a6), to 1.c4 he should reply with 1...a5, while any move of the b pawn will make central and axial symmetry coincide, so for example to 1.b3 black will reply with 1...b6. The idea is to keep doing this until a situation where two pawns are attacking each other. Then black should stop and think, because that will unbalance the position. So for example

1.a4 c5 2.c3 a6 3.b4

Here the "symmetric" move 3...b5 would lose, instead, black plays 3...cxb4 4.cxb4 b6! and wins. Note that this final position suggests to look at the even simpler position that follows.

Position 4

Here the situation is almost trivial: white is in Zugzwang, we see that. But trying to verbalize the principle we realize that it sounds as follows: copy white's moves according to axial symmetry until two pawns attack each other, then stop and think. So with three pawns we had central symmetry, with two, we have axial symmetry (with one pawn the two symmetries collapse to one symmetry so there is no point in examining that concept). This fact suggests that if there is an odd number of pawns then central symmetry will work, if instead there is an even number of pawns then axial symmetry will work. So in our 4 vs 4 situation (position 1) we might want to try axial symmetry. Of course if axial symmetry works there, it only works to some extent (remember that Position 2 is strangely a win for white).

I believe this gives a lot of importance to the strategy of looking at simpler problems when facing a big problem. It gives you ideas, your brain starts working well :)

So far what I know for sure is that in position 1 axial symmetry should be a good thing to try. I will need some more time to formalize the concept.

In the meantime I suggest a possible field of research. Consider the following game: place the pieces in the initial position and remove all the pieces that are not pawns.

Then play with the usual rules of chess. The aim of this game is to achieve one of the following two things:

a) promotion of a pawn;
b) the opponent is out of moves.

The general strategy should be to try to keep some kind of symmetry, and since only black can do this (because any white move now will break any imaginable symmetry), black probably has a forced win.

But is this known? Not by me :-)

Two knights against three pawns

Today I tried to do something and I came up with the following position. Black to move and draw.

The main line goes 1...Nf6 2.h6 Nxf5 3.h7 Nxh7 4.gxh7 Nd4! 5.h8=Q stalemate. In case of 5.h8=R it's a draw by perpetual check.

Blindfolded chess

Today I did something else, other than deciding to start a chess blog. I started to solve few-pieces endgame studies blindfolded. It's nice.

Let me tell you how it started. I was exploring Tim Krabbe's webpage and I found this chess blindfold trainer.

I realized that it's not so impossible to solve stuff blindfolded. For example (try to do it blindfolded) what's the winning move after

1.d4 Nf6 2.c4 c5 3.d5 b5 4.cxb5 a6 5.Nc3 axb5 6.e4 b4 7.Nb5 Nxe4

? Think about it. The solution is 8.Qe2 with the idea of capturing the knight. If the knight moves then Nd6# is mate! (select it with your mouse)

I also managed to solve the following study blindfolded. White Ka1 Ra2 Pc6; Black Kb8 Rc8 Pa7 Pb7. Give it a try :-)

See you soon.

Pilot

Hello, my name is Martino, I'm italian but I live in Brazil. I want to try to talk about chess related stuff.

So, last week I was looking at the following wonderful study (Prokes 1946). White to play and win.

Here is the solution (select it with your mouse): 1.Kd2 f2 2.Rd1!! g2 3.Ke2+ and wins.

Another great one is the following (Troitzky 1895, Hannemann 1915).

White to move and win. Solution: 1.d7 Rg6+ 2.Ke5 Rg5+ 3.Ke4 Rg4+ 4.Ke3 (or 4.Kd3 Rg1 5.Kd2 Rg2+ 6.Kc3 Rg3+ transposing to the main line) Rg3+ 5.Kd2! Rg2+ 6.Kc3 Rg3+ 7.Kc4 Rg4+ 8.Kc5 Rg5+ 9.Kc6 Rg6+ 10.Kc7 and wins. Note that white cannot allow the black rook to get to the d file and has to take care of the fact that if the white king moves to the d file, for example Kd4, then black plays Rg1! with the idea of a skewer on the d file.

The previous study follows, I would say, from the extremely famous Saavedra-Barbier study (1895), which is the following (white to move and win).

Solution: 1.c7 Rd6+ 2.Kb5 Rd5+ 3.Kb4 Rd4+ 4.Kb3 Rd3+ 5.Kc2 Rd4! 6.c8=R!! (6.c8=Q? Rc4+! 7.Qxc4 stalemate) 6...Ra4 7.Kb3!! and wins.

This gave me the idea of trying to compose chess endgame studies, and let me tell you, it's not easy.

First of all I looked for chess study databases, and I found this.

The study above (the first displayed in this post) is included, and in fact it's only here that I found who composed it. Someone called Prokes in 1946.

So as I was saying I started trying to compose and the first idea that I had was to use the tablebase as a support:

The idea is very simple: set up any position with at most 6 pieces and the "magic" tablebase will solve it for you. Not as a chess engine solves it but as a mathematician would solve it. If it's draw, he tells you that it's draw and the move. If it's not draw it tells you how many moves the winning side needs to checkmate the opponent and he gives you the move. You can make that move, and in the resulting position he will tell you the same thing (who wins and the move). You don't need to be a mathematician (although maybe you do) to know that this process gives the exact and complete solution of every position with at most 6 pieces (when I say 6 pieces I'm including the kings .. kings are pieces aren't they?).

So what did I try to do? I tried to set up some positions to see what happened. At some point, I don't remember how, I was dealing with the following tricky position (white to move).

It's tricky because there is only one winning move, and it's 1.Kc4. The idea is 1...Rxd6 2.d5+! Ke5 3.Re7+ cutting off the king, and now it's a basic win using the Lucena maneuver. If instead 1.Ke4? then 1...Re5+! leads to a draw (although it's enough to play 1...Ra5). The idea is that the white king cannot go forward.

Ok, so you might say, what does this have to do with anything? My idea was to create a study that reached the above position in the main line.

This is an example (although quite trivial). The line goes 1.Rxh7 Rxc5 (1...Kxc5? 2.Rh5+! Kb6 3.Rxa5 Kxa5 4.c7 wins) and we are back to the previous position. But this is too trivial. The following also is too trivial.

Here the idea is 1.Nd3+ Kd6 2.Nxc5 Rxc5.

The following is also trivial.

Here the idea is to take twice on c5. The problem, or I should say one problem, is that the first move is not unique, white having the choice between bxc5 and dxc5. Notice that of course it is not just a matter of finding a winning combination. You need to create a position (like this one) where there is only one winning move/idea. So you need to check that cxd5, cxb5 and Rh6+ lead to nothing.

The reason why they are trivial is that white is challenged with the choice between b4 and d4 only when the key position occurs. I would like a situation where white has to commit (choose between those two squares) before reaching the key position. Let me tell you again, this is not easy to achieve.

I'll try to work more on this and maybe I'll come up with something. Cheers :-)