Showing posts with label pawn majority. Show all posts
Showing posts with label pawn majority. Show all posts

21 February 2022

A Memorable Lesson

What are the plans for both sides?

White to move

Whenever an occurrence of a bishop on the wrong color squares in a pawn ending occurs, I recall a game I played in 1996. It was the first round of my second USCF rated tournament and I nearly beat one of the strongest players in my local chess club.* In the end, I had four pawns to two and opposite colored bishops. I was looking at this game anew a few weeks ago because I wanted to use it in the first of a series of lessons for some of the chess classes I'm teaching this month. These classes are organized by other people who supply me with students. They create a different theme each month, but I am at liberty to develop the theme as I see fit.

The February theme mentioned pawn structure and "lesser pieces", which I opted to make bishop and knights. I began with some elementary positions, such as one finds in Dvoretsky's Endgame Manual (2003).

Black to move

During the first session, I invited students to think through the plans for White from positions that arose in my 1996 game with Gary Younker. I make the point that I pursued a faulty plan because whatever the state of my understanding of the elementary position above, I failed to understand it well enough to deter me from futile efforts to promote my a-pawn.

From the diagram at the top of the post play continued:

55.Kg3 Bc6

After explaining to one group what White's plans should have been and demonstrating what seemed a plausible win, I tried against Stockfish. Here the silicon beast demonstrated that Black's resources were adequate after 55...Kd7

56.Kf4 Kb7?

White to move
57.g3?

Today, I would play 57.Kg5 with nary a thought. But, in 1996 I was obsessed with promoting my a-pawn.

57...b4 58.Ke5 Kc7 59.Ke6

59.Kf6 seems better.

59...b3 60.h4 b2 61.Bxb2 d4?

Gary was pleased with this move. After the game, he taught me some important lessons, criticizing my early c4-c5 in the opening because it "released the tension" and explaining that he sacked this pawn to create the fortress that ensued.

White to move

62.Bxd4??

Remarkably, I still had a winning position until this error. About half of my students who have seen this position have suggested 62.exd4, which creates a more useful passed pawn.

62...Bxf3=

The game went on another 14 moves with an exchange of my e-pawn for Black's f-pawn and my futile and even silly efforts to trap Black's king on a8.

I finally replied to a draw offer from many moves earlier with assent after 76...Bg4.

White to move
The Game's Final Position



*Although I began playing chess with some seriousness in the 1970s, played some high school matches and at the Spokane Chess Club, and entered a couple of USCF correspondence events, I did not have a USCF OTB rating until I returned to active play in the mid-1990s following completion of graduate school.

25 July 2020

The Soul of Philidor

On the Origin of Good Moves Reading Log*

"[Pawns} are the very Life of this Game: They alone form the Attack and the Defense...". Many a contemporary chess enthusiast must have been amazed to read this solemn statement by Philidor, bestowing such honours on the modest pawns, of which Philidors's famous predecessors, Greco and the Italian chess school, thought so little.
Dražen Marović, Understanding Pawn Play in Chess (2000)
The first paragraph of Understanding Pawn Play in Chess is typical of the credit offered to Philidor for his innovative ideas presented through a handful of composed games that he published in Analyse du jeu des échecs (1849). Willy Hendriks challenges conventional understanding in On the Origin of Good Moves (2020). Consider these two positions from quizzes in Hendriks's book (25, 57).

Black to move

Black to move

Both exercises offer the same choice: dxc4 or bxc4. There are three questions. How would you play each position? How would Greco play? How would Philidor? The answers may surprise you.

In a USCF online rated blitz tournament yesterday, I had this position.

White to move

I played the move that Greco would have selected. Ironically, this choice helped me play somewhat in the manner advocated by Philidor, but only after I spurned his general principle for pawn captures. I even sacrificed a knight to get my pawns rolling.

The short version of what On the Origin of Good Moves has argued through the first four chapters is this: Greco is somewhat underrated by chess writers and may be worth more attention. Philidor, on the other hand, gets a free pass concerning egregious errors in his analysis. His reputation for making an original contribution to chess theory might be somewhat greater than deserved.

The first two quiz questions at the beginning of the first chapter on Philidor offer positions from his games. ChessBase Meg 2020 and many books endorse Philidor's evaluation of the position. Willy Hendriks and Komodo 15 disagree.

*See "On the Origin: Reading Journal".

15 September 2019

Fidelity Chess Challenger

Several years ago, my wife's uncle gave me an old stand alone chess computer, Fidelity Chess Challenger. Last night, I searched and found an instruction manual online for Chess Challenger 7, which appears to have the correct instructions. I played a game on its top level--level 7. Based on research presented in the HIARCS chess forum, I believe the device was manufactured in 1980.


In the image above, the machine has played its move as O-O-O by indicating that it moves its king from e8 to c8. That move puts my king in check.

In my game, I played quickly while also reading a book. On its top level, Chess Challenger requires several minutes per move for most moves. I was reading in another room, would read a page or two, and then check on the machine. I recorded the moves on another device that allowed me to quickly email the completed score to myself.

Chess Challenger played a decent opening, reached a winning position in the middle game, and then revealed substantial weaknesses in endgame understanding. It demonstrated understanding of exploiting a pin, and using forks. It also set a simple stalemate trap near the end of the game.


Stripes,James -- Fidelity Chess Challenger [C68]
14.09.2019

1.e4 e5 2.Nf3 Nc6 3.Bb5 a6 4.Bxc6 dxc6 5.d4

Probably a weak move on my part. I rarely play the Spanish Opening, and the exchange variation is not my usual choice when I do.

5...Bg4

5...exd4 6.Qxd4 Qxd4 7.Nxd4 seemed okay to me.

6.dxe5 Qxd1+ 7.Kxd1

This is the position in the photograph.

7....0-0-0+ 8.Ke2

Black to move

8...Bc5

This move struck me as odd.

8...Re8 9.Bf4 f6 10.Nbd2 fxe5 11.Bg3 Nf6 12.Rhe1 Bd6 (a later game continued 12...Nh5 13.Kf1 Nxg3+ 14.hxg3 Bc5 15.Nc4 Rhf8 16.Ncxe5?? Rxe5 17.Re2 Rh5 18.Rd2 0-1 Luptak,P (2086) --nZvarik,M (2245), Slovakia 2010.) 13.Kf1 Nh5 14.Kg1 Nxg3 15.hxg3 h5 Black won in 61 moves Aleksandrova,D (2015) -- Yilmaz,G, Albena 1977.

8...f6 9.h3 (9.Nbd2 Re8 10.h3 Bh5 11.Nf1 fxe5 12.Ng3 Bg6 13.Be3 Nf6 14.Nd2 Nd7 15.Rhd1 Be7 16.f3 Rhf8 White won in 54 moves Kieninger,G (2509) -- Rellstab,L (2478), Bad Oeynhausen 1941) 9...Bxf3+ 10.gxf3 fxe5 11.Bd2 Ne7 12.f4 exf4 13.Bxf4 Ng6 14.Bg3 Re8 15.Nd2 Bd6 Black won in 46 moves Babula,M -- Dobrovolsky,L, Brno 1969.

9.Be3 Bxf3+

This move does not exist in my database.

9...Bxe3 10.Kxe3 f6 11.Nbd2 Re8 12.exf6 Nxf6 13.Rae1 Nd5+ 14.Kd4 Nf4 15.h3 Bh5 16.g3 Ne6+ 17.Kc3 Bxf3 18.Nxf3 Rhf8 19.Re3 Nc5 and Black went on to win a pawn ending after a lot of middle game manuevering in Toumaniantz,R (2162) -- Duflot,S, Le Touquet.

If there was any sort of opening tree built into the software, it could have included moves from Lasker -- Pollock 1892.

9...Be7 My database shows four games with this move 10.h3 No other game in the database has this position. 10...Bh5 11.Nbd2 f6 12.Rhd1 fxe5 13.g4 Be8 and Black won in 42 moves Lasker,E -- Pollock,W, Baltimore 1892.

10.Kxf3

10.gxf3 might not be bad.

10...Bxe3 11.Kxe3 Nh6 12.h3 Rhe8 13.f4 f6

White to move

14.exf6??

14.Nc3 fxe5 15.g3 exf4+ 16.gxf4 Nf5+ 17.Kf3 Nd4+ 18.Kg3 Nxc2 19.Rad1 Black should win the ending;

14.g4! fxe5 15.f5 White's kingside majority is more dangerous than Black's queenside. Such endings, as I understand, are a principle reason for playing the exchange variation of the Spanish.;

14.Nd2 fxe5 15.f5.

14...Nf5+

I had underestimated this move, having mainly assured myself that I would not lose the rook on a1.

15.Kf2

15.Kf3 Nd4+ 16.Kg4 Nxc2 and Black wins material.

15...Rxe4

15...Nd4? 16.Nc3 Nxc2 17.f7 (17.Rad1 Rxd1 18.Rxd1 gxf6).

16.g3

I realized by this point that I was clearly worse.

16...gxf6 17.Nc3

Black to move

17...Re3?

I expected 17...Rd2+ 18.Kf3 Re8 19.Kg4 Ne3+ 20.Kh4 Rxc2-+

18.Rad1 Rxd1 19.Rxd1 Rxg3 20.Ne4

Black to move

20...Rxh3 21.Nxf6 Rh2+ 22.Kf3 Rxc2 23.Rg1 Nh4+

23...Kd8 24.Rg8+ Ke7 25.Ne4

24.Ke4

24.Kg4 Ng6 25.f5 Ne7 26.Nxh7

Black to move

This is the type of position I like putting in front of my students. Black is clearly better, but must find a plan to neutralize White's threats. For brute force calculation with limited depth, positional understanding is vital. Chess Challenger showed the weakness in its primitive programming at this point.

24...Rg2?

This move surprised me, as my f-pawn seems dangerous in the knight ending.

24...Ng6 Before playing Rg1, I had looked at 25.f5 Ne7 26.Rg7;

24...b5! avoids the checkmate threat and gives White queenside problems that cannot be met.

25.Rxg2 Nxg2 26.Nxh7

This move was not so much to grab the pawn, although useful, as to clear the f-file and control the promotion square.

26...b6

Chess Challenger's moves stopped making sense to me here. Prior to this point in the game, I had foreseen most moves.

26...Kd7 27.f5 (27.Ke5 Ne3 (27...Ke7 28.f5 Nh4) 28.b3 Ke7 29.Nf6) 27...Nh4 28.Kf4

27.f5

Black to move

27...Ne1??

This move is a game losing blunder that highlights that Chess Challenger is oblivious to the dangers presented by my passed pawn.

27...Kd7 or Kd8 are the only moves that do not lose. 28.Ke5 Nh4 29.f6 Ng6+ 30.Kf5=.

28.f6+- Nd3

28...Kd7 29.f7 Ke7 30.f8Q+

29.Kxd3

However, it is possible that the software saw 29.f7 Nc5+ 30.Kf5 Nd7 in which case the knight is still lost, but White does not yet have a queen and there is a lot of work to do to use the knight to convert a pawn minority into a passed pawn.

29...c5 30.f7 a5 31.f8Q+ Kd7 32.Nf6+ Kc6 33.a4 c4+ 34.Kxc4 Kb7 35.Qf7 Ka8!

I was impressed with the stalemate trap set here.

White to move

36.Kb5

36.Qxc7 b5+ 37.axb5 (37.Kxb5 stalemate) 37...a4 38.Nd5+-

36...Ka7 37.Qxc7+ Ka8 38.Ka6 b5 1-0

Chess Challenger made this move and then lit the "I lose" light.

17 August 2019

An Exercise

This week's lessons with my chess students have focused on queenside pawn majorities. We look at a couple of games played by Mikhail Botvinnik, an endgame that Seigbert Tarrasch blew against Emanuel Lasker, and this position that I created.

White to move

We start with the pawn exercise, and I do not initially tell the student who is to move, nor our theme concerning queenside pawn majorities. If the student thinks the position is equal, I play White. If they think one side is winning, they get that side and get to move first.

Try it against a friend or your computer.

Then, Lasker -- Tarrasch, St. Petersburg 1914.

Black to move

We play it out. I take White.

Then we look at Botvinnik -- Kmoch, Leningrad 1934 and Botvinnik -- Konstantinopolsky, Sverdlovsk 1943. If enough time remains, we go over a game that I played a few years ago (see "Excelling at Technical Chess").

The lesson and much of its content was inspired by Max Euwe, Judgement and Planning in Chess (1953).