15 July 2017

Checkmate Patterns

Some readers of Chess Skills may have been disappointed that my postings have been limited the past two months. Much of my chess time has been devoted to preparing lessons for my camp in August. A standard feature of my annual summer chess camp has a been a camp workbook that each student receives. This year's workbook will be more than twice the size of my previous largest, which ran 92 pages. This year's workbook will be available through Amazon. My title has changed three times in the past two days. Currently, my working title is Five Days to Better Chess: Essential Tools.

In this summer's camp, each day will be focused on one topic. Each topic will be layered to accommodate students of a wide range of skill levels. There will be group activities and individual activities. The topics in sequence are checkmates, endings, middlegames, openings, and great games.

On the first day, beginning students will learn three basic checkmates against a lone king: queen and king, rook and king, and queen and rook. Then, they will move on to where the second tier group begins. Here is a sample from my workbook in progress.

Checkmate Patterns

It is not clear precisely how many ways exist to deliver checkmate. Nonetheless, my study of many thousands of checkmates in my games and in the games of others has convinced me that there are only a few dozen basic checkmate patterns. Most opportunities to force checkmate will fall into a much smaller set, perhaps two dozen. My research is not original, but merely confirms what many chess masters have found through the ages.

My booklet, “A Checklist of Checkmates”, lists 37 patterns. Portions of this booklet have been distributed to my students for the past fourteen years. The booklet contains illustrations of patterns from games, followed by exercises.

Several books have helped me learn and teach these patterns. The best one in my view is The Art of the Checkmate (1953) by Georges Renaud and Victor Kahn. When I wrote “A Checklist of Checkmates”, the English translation of The Art of the Checkmate was available only in descriptive notation, which few children learn these days. Since then, it has been republished in algebraic. After The Art of the Checkmate, the most useful book that I have found is Mikhail Tal, and Victor Khenkin, Tal’s Winning Chess Combinations (1979)—this book is new to me, having purchased it a few months ago.

Tal and Khenkin arrange their book with one chapter for each piece, followed by combinations of pieces: rook, bishop, knight, queen, pawn, two rooks, queen and bishop, and so on. Each chapter presents a small number of essential patterns. This arrangement is similar to the arrangement that I created for “A Checklist of Checkmates”, reproduced here.

The Checklist

Corridors
1.Back-rank mate
2. Edge-file mate
3. Two rooks (or rook and queen)
4. Two pigs
5. Anastasia’s mate
6. Max Lange’s mate

Diagonals
7. Fool’s mate
8. Boden’s mate
9. Parallel diagonals
10. Reti’s mate

Intersections
11.Rook and bishop
12. Opera mate
13. Pillsbury’s mate
14. Morphy’s mate
15. Two rooks and bishop

Knights
16. Smother mate
17. Smother mate with pin
18. Two knights
19. Corner mate
20. Arabian mate
21. Modified Arabian mate
22. Knight and bishop mate

Queens
23. Edge checkmate
24. Swallowtail
25. Dovetail
26. Epaulette
27. Half-epaulette
28. Queen and bishop
29. Queen and knight
30. Queen and rook

Combinations
31. Legall’s mate
32. Lolli’s mate
33. Mayet’s mate
34. Anderssen’s mate
35. Blackburne’s mate
36. Damiano’s mate
37. Greco’s mate

Just as there is no certain definite number of possible patterns, there is considerable variety in the naming of patterns. For example, my “two pigs” checkmate has been called “blind swine checkmate” in other books, including Vladimir Vukovic, The Art of Attack in Chess (1965). I dislike the name blind swine because that term’s origin comes from a grandmaster discussing a situation when two rooks could force a draw, but not force checkmate—hence, they are blind. I see blind swine as a drawing combination, not a checkmate pattern. Rooks on the seventh rank are sometimes called pigs, or swine.

Although there is not universal agreement on the number and names of common checkmate patterns, many of these names are in common use. An entry on Wikipedia lists many of them. Some names, such as Reti’s mate and Anastasia’s mate, have very specific histories. On the other hand, one name, Pillsbury’s mate, comes from a specific game that was not played by Pillsbury. Renaud and Kahn present the game as one of his, although it was played by others. There are several important ideas in chess that are misnamed from a historical point of view. For example, the Lucena position (part of the second day lessons) does not appear in Luis Ramírez de Lucena, Repetición de Amores e Arte de Axedrez (1497).

Of central importance are the patterns themselves. If learning the names helps you learn patterns that you will see often, then they are useful. Knowing the name is not essential to perceiving the pattern. For most chess players, the name is a useful memory device.

08 July 2017

Three Tactics

A pin, decoy, and fork often work together to exploit an elementary error. Sometimes, exploitation of the error is complex, but it remains rooted in a fundamental pattern that should be well-known.

A few days ago in an online blitz game, I had this position.

White to move

I executed the pin. Rather than capturing my bishop (the decoy) and facing the resulting fork, my opponent resigned.

The pattern appeared in Greco.

White to move

Greco's game concludes: 12.Bb5 Qc5 13.Be3 Qxb5 14.Nxc7+ Kd8 15.Nxb5 1-0

This game deserves inclusion in all packages of instructive material to be used with beginners. My search of my largest database for positions with a White knight on d5, a Black queen on c6, and the move Bb5 (including all mirror positions with colors reversed) turned up well in excess of 400 games. Most led to defeat for the player whose queen was attacked, but not in every case.

I turned up this interesting position from the women's championship of France in 1931, the game Bastin -- Freeman, Paris 1931.

White to move

I posted this position in several fora on Facebook, but few responses identified the key move that begins the winning sequence.

9.b4 and the queen is trapped. 9...Qc6 10.Bb5 and Black resigned because 10...Qxb5 offer White the choice of capturing the queen--an error--or checkmating the Black king.

In Fries Nielsen -- Liersch, Germany 1980, White won Black's queen. However, Black gained more than sufficient material compensation for the queen and went on to win.

White to move

14.Bb5 axb5 15.axb5 Qxd5! 16.exd5 Rxa1 and Blkack has a rook and three minor pieces for a queen and two pawns.

05 July 2017

Blundering into Victory

On Monday, David Griffin and I met at the Spokane Valley Library to play our game in the Spokane Contenders. This six player round robin began in early May and must be completed by early August. The winner faces Michael Cambareri in the City Championship. Our game was Griffin's fifth and my first. I stated to those who asked that I would play all of my games in July.

This game was the second time that I faced Griffin's Nimzo-Larsen Attack. In the first, I opted for an attempt at tactical refutation, came out of the opening slightly worse, but then was able to gain the advantage when Griffin missed a knockout blow. I opted for a positional response this time and secured a clear space advantage from the opening. As I was playing for checkmate, I made a few errors that let my opponent crawl back into the game. He missed his chances, though, and I had a slight edge in the endgame.

Then, I blundered throwing away the game. This blunder, however, proved to be the game winning move.

Griffin,David (1523) -- Stripes,James (1841) [A06]
Spokane Contenders Spokane, 03.07.2017

1.Nf3 c5 2.b3 Nf6 3.Bb2 d5 4.e3 g6 5.Be2 Nc6 6.0–0 Qc7N

I was pleased to reach nearly the same position I had against Michael Cambareri when I beat him in seventeen moves, but with colors reversed. I contemplated whether lack of deployment of the bishop to g7 was of any account.

6...Bg7 7.Ne5 (7.d4 cxd4 8.exd4 0–0 9.c4 dxc4 10.bxc4 Ne4 and drawn in 51 moves Rethy,P [2389] -- Szabo,L [2537], Budapest 1940) 7...Nxe5 8.Bxe5 0–0 9.Qc1 Ne8 10.Bxg7 Nxg7 11.f4 Qd6 and drawn in 36 moves Trompowsky,O (2366) -- Cruz,W (2307), Rio de Janeiro 1940.

7.d3

Griffin spent twenty minutes on this move.

7.c4 d4 8.exd4 cxd4 9.Nxd4 Qe5 would have pleased me.

7...Bg7 8.Nbd2 0–0 9.h3 b5

White often plays b4 against the QID. Indeed, A row of pawns on d4, c4, and b4 occurred in several of the games I went through preparing for my Club Championship battle with Michael.

10.Nh2

I was impressed that all of White's pawns are capable of moving to the fourth rank. While it appears that I am gaining space with my pawns on the queenside, I could easily find myself in possession of a fragile center.

Black to move

10...e5

10...Bb7 11.f4 and White will post a minor piece on e5.

11.f4 d4 12.fxe5 Qxe5

12...Nxe5 would be a gross error 13.exd4 cxd4 14.Bxd4±.

13.e4

Black has more space, leading to greater mobility and flexibility. And yet, it is not entirely clear how to proceed. I would like to exploit some apparent weaknesses around the White king, but the defensive forces seem adequate. Before my queen can profitably occupy the weakened g3 square, White must commit a knight or bishop to f3.

13.exd4 Nxd4 14.Nhf3 Qe3+ 15.Kh1 Bb7 16.Bxd4 (16.Nxd4 Qxh3+ 17.Kg1 Qxg2#) 16...cxd4.

13...Be6

I didn't like 13...Qg3 14.Rf3.

13...a6 was a move that I considered, but regarded as slow. Still, it increases the mobility of my rook on a8, which could then lift to the seventh rank. It also transfers the onus of making important strategic and tactical decisions to my opponent.

14.Ng4 Nxg4

14...Bxg4 15.Bxg4 Bh6.

15.Bxg4

Black to move

15...f5

This forcing sequence left me with a weak f-pawn, but also opened the g-file for my heavy pieces. I considered 15...Qg3 16.Rf3 Bxg4 17.Rxg3 Bxd1 18.Rxd1 when it was not clear to me that I had gained anything from the material exchanges. I needed to win this game, so eschewed simplification that did not lead to clear advantage.

15...Bh6!? 16.Bxe6 Be3+ 17.Kh1 Qxe6.

16.exf5 gxf5 17.Bf3 Rac8 18.Re1 Qd6

What has become of my advantage? My forces are in retreat. And yet, I was confident that retreat was merely redeployment and that White's forces lacked coordination.

19.Nf1

19.Bxc6 seems worthy of consideration in view of the principle that a player lacking space should exchange pieces.  19...Rxc6 But, this rook will soon come to g6 and the pressure on g2 may be too much for White.

19...Ne5 20.Nh2

20.Bc1 f4 (20...Nxf3+ 21.Qxf3 Bd5 22.Bf4 Qc6 23.Qf2) 21.Nd2.

20...Rf6

20...Nxf3+ 21.Nxf3 Bd5
20...Bh6 with plans to play Be3+.

21.Bc1 Rg6

White to move

22.Kh1?!

22.Bh5! Bd5 (22...Rf6 23.Bf4+-) 23.Bxg6 Qxg6 24.Re2 Nf3+ 25.Nxf3 Bxf3 26.Bf4 and the game favors White. Black can win back the exchange, but has a weaker pawn structure.

22...Nxf3 23.Nxf3 Bd5 24.Bd2

Black to move

24...Rg3!

24...Qg3 25.Rg1 (25.Re2 Bxf3–+) 25...Re8.

25.Rf1 only move Re8

I underestimated 25...Qg6 26.Rf2 Bxf3 27.Rxf3 Rxg2 28.Qe1.

26.Be1 Rg6 27.Nh4 Re3! 28.Rf3 only move

28.Nxg6 Rxh3+ 29.Kg1 Qh2+ 30.Kf2 Qxg2#.

Black to move

28...Bxf3

28...Rge6 29.Bf2 Bxf3 30.Nxf3 Re2 was a better means of keeping control of the game.

29.Nxf3 Qd5?!

I wanted to maintain the pin on g2 with its attendant checkmate threats. I considered 29...Rge6 which would have been more logical. There is no realistic chance to find checkmate, but domination of the open file keeps White's pieces in a passive role.

30.Bf2 Re7

Again, my forces are in retreat.

31.Qf1 Bh6! 32.Re1 Be3 33.Nh4 Rge6

At this point in the game, I sensed that I had let my advantage slip away. However, Stockfish insists that my advantage is as strong as it had been at any point prior. Nonetheless, it would slip away soon.

33...Rh6 34.Nf3 (34.Bxe3 Rxe3 35.Rxe3 dxe3 36.Nxf5 Rxh3+ 37.Kg1 and what will I do about Ne7+? ) 34...f4.

34.Bxe3

Black to move

34...dxe3?

34...Rxe3 was best

a) 35.Nxf5 Rxe1 (35...Rxh3+?? 36.Kg1 Rxe1 37.Qxe1 Qxf5 38.gxh3=) 36.Nxe7+ Rxe7–+.

b) 35.Nf3 Rxe1 36.Nxe1 Qe5–+.

c) 35.Rxe3 dxe3 (35...Rxe3 I had examined 36.Nxf5 Rxh3+ 37.Kg1 Re3 38.Nxe3 dxe3=) 36.Nxf5 Re6–+.

35.Qxf5 Re5

35...Qxf5 36.Nxf5 Rf7 37.g4 e2 was not to my liking.

36.Qg4+ Kh8 37.Qc8+ Re8 38.Qg4 Rg8

38...Qd4! Black maintains a clear advantage in all lines.

39.Qf4

39.Qe2 Rf8.

39...Reg5

39...e2

40.Qf6+ R5g7 41.Rxe3

Black to move

It has become clear that not only have I squandered an advantage, but am in danger of losing.

41...Qd4?

I regretted not playing this move three moves earlier and now felt that it was forced, completely missing White's refutation.

41...a5 42.Re5 Qf7 43.Qxf7 Rxf7 44.Rxc5±
41...Qf7= with equal chances for both sides.

42.Qxd4

42.Re5±

42...cxd4 43.Re4

43.Re2 is probably equal.

43...Rc7

I still have hope of advantage with a pawn exchange because my rook also restrains the enemy king, while my own king might join the fight.

44.Rxd4 Rxc2 45.a4 bxa4 46.Rxa4

Black to move

46...Ra8

46...Rg7 was the correct way to defend the pawn, keeping pressure on g2.

47.d4 Rb2 48.b4 Kg8 49.Nf5 Kf7 50.g4 Kf6

50...Kf8 would have been a beautiful prophylactic move.

51.h4

Black to move

51...Rc8??

Right idea, wrong square.

51...Re8 52.Ra6+ Re6 53.Ra1 a6 and Black is pressing with the advantage.

52.Rxa7??

With both his rook and my pawn still in his hand, David saw the ensuing checkmate and resigned here. Having touched my pawn, he could no longer retract his move.

52.Ra6+ Kf7 53.Nd6++-.

0–1