Sunday, August 13, 2006

Studying chess endgames: how important are pawnless positions?

I finally started to study chess endgames and decided that it might be best to actually start at the beginning of the book (I am currently using Bruce Pandolfini's "Pandolfini's Endgame Course"). However, every endgame book I looked into starts with studies of elemental checkmates and other positions without pawns. However, positions without pawns rarely occur in chess games. This makes me wonder if it actually makes sense to spend a lot of time analyzing these positions.

First of all, one might say that pawnless positions are much less complex than positions with pawns. Therefore, it cannot possibly take that much time to go through these introduction(?) chapters. To my surprise, it turned out that even in clearly won positions it can require accurate play to actually execute the win. As Blue Devil Knight also reported recently, examples such as K+B+N vs. K are definitely won but can be tricky to execute even for good players. Therefore, it takes a lot of time to develop an understanding of even the most basic positions, the elementary mates.

This week I decided to "graduate" from the elementary mates and to move on to the battle between heavy pieces. In general, the queen (white) wins against a single rook (black). However, black has drawing chances if she/he manages to keep the rook next to the king. Among the chess positions analyzed by and named after the chess master Francois-Andres Danican Philidor (1726-1795) is also the queen vs. rook endgame position shown on the left. This is a zugzwang position. With black to move and forced to move her/his rook away from the king, white wins quickly. Regardless which move black chooses, white can either checkmate or capture the black rook with a queen fork. For instance, the only legal move for the black king, 1. ... Kh6 allows white to pin and capture the rook with 2. Qf8. Moving the rook by playing, e.g., 1. ... Ra7 enables white to capture it by 2. Qe4+ Kh8 3. Qh1+ Kg8 4. Qg1+ forking black's king and rook. However, it is white's move. White's goal is to get in the same position as shown above, but with black to move. This can be achieved by playing 1. Qe4 Ka8 2. Qa8 Kh7 and after 3. Qe8 the pieces are back on their original positions with black in zugzwang. White wins as described above.

As mentioned above, it took me quite a while to comprehend Philidor's position. One of the reasons for my troubles studying these seemingly simple chess positions is that I am still not able to analyze variations longer than, say, 2 moves. In chess endgame positions, the number of possible moves is typically much lower than in typical middlegame positions. However, it is often necessary to carefully analyze much longer variations to prevent the opponent from escaping or even forcing a draw. As a consequence, I came to the conclusion that studying very basic endgames will probably help me to improve my general ability to analyze positions.

7 Comments:

Blogger transformation said...

sciurus, i am enjoying your post. and am adding your link.

question, please: this is unclear to me. you write and talk--and i say this without any hint of sarcasm please--like an experienced chess player, yet also say you are getting back to chess or starting out. had you played before? or totally new to the game?

i played intensely 1972-1973 and almost to to 1700 back when ratings were not inflated--age 15 then. now i am about 1650, and it has taken me five years--age 48. i did not look at chess for 28 years, while i practiced architecture, zen, worked an intense stint on wall street, and now work at a home depot type place. but i know where all the items go as a chess player/architect/broker! statistical arrays and complex systems! survival.

i love to study. i also greatly appreciate the many smart persons at CTS who, as it turns out, also blog here. you can see me at CTS as dkTransform 1486, 83.8% for 16,500 problems. my RD is usually around 20 to 24, but am taking a short term break to re-establish my use of ctArt3.0.

there is much that i can say, or happy to add, but not appropriate till i know your level. about what is your elo, if i may please ask? thanks for the link. but i already have chessBase9, but have yet to put it to full use, as my coach got me the software.

warmly, david

2:31 PM  
Blogger sciurus said...

David, thanks for the comment and flattery :-)

I really started playing beginning of 2006 with a few very short tries before, see my post on how I got into chess. I don't have a real rating. My time for playing is a bit limited. Therefore, I mostly play correspondence chess which is great if you want to analyse your moves carefully yet don't have a free block of time large enough for a slow game. The ratings at ChessWorld are very inflated, so this won't tell you much either (my rating there is around 1550, which is considered as decent beginner).

You certainly have diverse experiences! Keep up the good work and have fun.

3:46 PM  
Blogger Loomis said...

In terms of direct practical application, pawnless endings are rare. However, studying the Queen and Rook ending you have shown is important for a couple reasons. The simplest is that rare doesn't mean never, and when it does come up, you'll want to win.

The second reason is that if you want to learn about double attacks by the queen, the position you've shown is a good playground. For example, try figuring out how to fork the king and rook for every square the rook could move to. Some will be easier than others, some will involve both ideas and calculation.

For example, you give one sample line starting with 1. ... Ra7 2. Qe4+ Kh8. But what if black tries 2. ... Kg8? Here getting the fork requires a useful to know manoever by the queen, 3. Qf4+ Kh8 4. Qh3+ Kg8 5. Qg3+ Kh8 6. Qh2+ Kg8 7. Qg1+ with the fork. Notice that the queen avoids g2 because it's the only square that allows Kf8 without immediate mate.

Also, you say 1. ... Kh6 is immediately punished by mate. I don't see the immediate mate, but there is Qf8 pinning the rook and taking it next move. After Qh8+ Rh7 Qg8 threatening mate, black has the clever Rf7+ trying for Qxf7 stalemate! Of course, white does not have to play Qxf7 and will just move the king and still be winning.

So, while positions like this aren't very likely in game play, you'll be happy to have studied them if they do occur, and they provide lots of fundamental calculation and vision practice even if they never do.

6:13 PM  
Blogger Temposchlucker said...

K+Q vs K+R is one of the most difficult endgames around. In the early days (before endgame databases) they thought it was a relative easy win. As you have showed in your post. But since then the computer has discovered much more resources for the defending side. For fully understanding you need an endgame database like Nalimov.

1:52 PM  
Blogger sciurus said...

Loomis: thanks for the comments and analysis. I fixed the mistake with 1. ... Kh6.

Regarding your comment on the example line with black to move and 1. ... Ra7 followed by 2. Qe4+ Kg8. The best line is 3. Qd5+ Kh7 (Kh8 does not make a difference) 4. Qh1+ Kg8 5. Qg1+ wins the rook. As suggested by Tempo, this time I verified it with the tablebases :-)

3:29 PM  
Blogger sciurus said...

Tempo,
thanks for the insight. I tried to get the Nalimov tablebases to work in my beloved Scid, but did not succeed so far. For now, I am working with the Shredder online databases. As Loomis' comment shows, I should have done so earlier!

3:31 PM  
Blogger Loomis said...

sciurus,

Wow, that is much easier than the line I gave, nice find. For some reason, it's so easy to miss things like that, which is why even these simple positions can provide useful practice.

8:13 PM  

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