26 January 2022

The Bad Pin

A pin is a restrictive contact that either prevents a piece from moving because doing so would violate the rules of the game (absolute pin), or that discourages moving the piece because the consequences could be dire (relative pin). Pins can be potent weapons in the chess struggle (see "A Lesson in Pins").

Relative pins are double edged. They can backfire, presenting the player facing the pin with an opportunity. Many of my students the past two weeks have seen this position from a game I played 16 January on Lichess.

White to move
After 5...Bg4??
How should White deal with the pin on the knight? Once you understand certain patterns, the correct answer is instantaneous. 

Evidently I am not the only player who has had this exact position. The position just before I played 8.Qxf7# has been examined in the ChessBase cloud more than 1500 times. Certainly some of the games that could have led to the moves in my game continued 6.Ne5 Bxd1 7.Bxf7#. It seems likely that a few players of the Black pieces also would have found 6...Be6 (the best choice after White exploits the bad pin).

Years ago, perhaps 1999, I bought and began reading Georges Renaud and Victor Kahn, The Art of the Checkmate, trans. W. J. Taylor (1953). I wrote about this book and how it first came to my attention in "Checkmate Patterns) (2015) and again in "Learning Checkmate (Or Teaching It)" (2021). I am rereading it, now in a new translation that has algebraic notation.

The Art of the Checkmate is my first recommendation when players are looking to learn checkmate patterns. Renaud and Kahn do far more than present basic patterns and then offer exercises. They offer detailed discussion of the variability of the basic pattern and how to bring it about. They use mostly full games. The chapter, "Legal's Pseudo-Sacrifice" (11-21) offers 17 complete games arranged by what they refer to as the "four aspects" of Legal's mate. They explain:
First and foremost we ask you not to learn it by heart but to grasp the precise mechanism, to understand that the bishop on g4 in "hanging", that is to say exposed to capture if the knight moves to threaten mate. But this mechanism appears in many positions as a latent threat and the opponent, if he pins your king's knight, is obliged to take this into account.
The Art of the Checkmate, trans. Jimmy Adams (2015)
I missed my chance to show the knowledge I should have acquired from the book in this blitz game played in 1999 on the Internet Chess Club.

White to move
Cleary, 9.Nxe5 is the correct move. I played 9.Nbd2, still managed to get a clear advantage, worked it into a decisive advantage, and lost on time in the endgame.

In 2000, I showed further incomprehension by maneuvering my way into the losing side of one of the combinational motifs enabled by "the bad pin".

White to move
My opponent understood the ideas and seized a clear advantage.

7.Bxf7+ Kxf7 8.Ng5+ Ke8 9.Qxg4

White has a decisive advantage and went on to win.

Genesis of the Instruction

It might be a stretch to claim that Renaud and Kahn invented the genre of checkmate pattern books. The manuscripts of Gioachino Greco, and many books grounded in these manuscripts offer more in the way of elementary checkmates than any sort of positional insight. But, when it comes to naming and classifying checkmate patterns, I know of nothing earlier than The Art of the Checkmate.

In the annotations to Kermer de Légall's famous game in the Jimmy Adams translation, Renaud and Kahn credit Emanuel Lasker with articulating a general principle of open games: "it is not always advisable to pin the opponent's king's knight before he has castled" (the 1953 translation makes no reference to Lasker). They are referring to lectures Lasker presented in London in 1895 and which were later published in outline as Common Sense in Chess (1917). I presented "Lasker's Rules" to my students and on Chess Skills in 2013, and then discussed Erik Kislik's (Applying Logic in Chess [2018]) critique in "Knights Before Bishops" (2018). It is notable that Renaud and Kahn qualify Lasker's rules in a manner that anticipates Kislik's critique. 

Lasker, Common Sense in Chess presents two short games at the beginning of the chapter. It is not clear that they derived from actual play as all the instances of his two miniatures that I find in the database are relatively recent (late-twentieth century to the present). This position arose in the second.

Black to move
6...Nxe4 7.Bxd8 Bxf2+ 8.Ke2 Bg4#

Renaud and Kahn begin with Legall's well-known game. However, the version they offer differs from that found in George Walker, A Selection of Games at Chess (1835). Edward Winter inquired in 2008 about the earliest known publication of Legall's game (Chess Notes 5720, 18 August 2008). Dominique Thimognier has been researching Legall and published some of the results in French at Heritage des Echecs Francais.

The variation presented in Walker is unsound. White blunders with 5.Nxe5. Yet, the Walker variation is the one found in ChessBase Mega 2020. Chessgames.com has the variation presented in Renaud and Kahn, but with White's rook on a1 absent.

Although there is plenty to doubt about the original game, the endless variations of the ideas have appeared in a great many games. Renaud and Kahn explicate the possibilities well.


I created an interactive lesson on Lichess.org with some instructive games and 20 exercises. The Study is called "The Bad Pin". I may add to it as I find time. Take a look. Let me know what you think.

14 January 2022

A Lesson in Pins

In my after school chess club at Saint George's School yesterday, I presented the game below to the students to highlight some basic principles for using pins effectively.

The player with the White pieces was William Lewis (1787-1870), a prolific chess author best remembered as one of those who hid inside the infamous fake chess playing machine called "The Turk".* Lewis was a student of Jacob Henry Sarratt, England's best player. I am drawn to Lewis because his Gioachino Greco on the Game of Chess (1819) offers more of Greco's model games than can be found in databases (see "Gioachino Greco on the Game of Chess"). Some of the positions in his other instructional books also are a regular part of my teaching.

Lewis,William -- Keen,Eric [C56]
London Casual Games London, 1817

1.e4 e5 2.Nf3 Nc6 3.Bc4 Bc5 4.c3 d6

4...Nf6 is the most popular move today, but 4...d6 is solid.

5.0-0 Nf6 6.d4

6.d3 seems better.

6...exd4 7.cxd4 Bb6 8.h3

Black to move

8...0-0 has led to better results for Black in current master play.


The first pin. We use the term pin when two pieces are attacked along a file, diagonal, or rank such that the one in front cannot move (absolute pin) or by moving exposes a piece of greater value to capture (relative pin).


A mistake.

9...0-0 is best 10.Rxe4 d5 restores the material balance 11.Bxd5 Qxd5 and White has a slight advantage.


10.Bg5 is also strong

10...Qxd5 11.Nc3

Piling on the pinned knight wins back the material and maintains substantial pressure on Black's position.


White to move

12.Nxe4 0-0 leaves White with only a slight advantage (12...Nxd4?? 13.Bg5! [13.Nf6+ Kf8 14.Re8+ Qxe8 15.Nxe8 Kxe8 16.Nxd4] 13...Nxf3+ 14.Qxf3 Qd4 15.Nd6+).


Moving another piece into a pin makes Black's troubles worse.

12...Kf8 and Black cannot castle. This move is Black's best choice. In either case, White already has a technical win.


Here, castling would lose the knight.

13...Be6 14.Bg5

Pinning the knight again

14...Qd6 15.Bxe7

Black to move

Now the bishop is pinned.

15...Qxe7 16.d5 0-0-0 17.dxe6+-

16.d5 Rhd8 17.Ng5

Piling on. The manner with which Lewis increases the pressure on Black's pinned pieces is instructive. 17.dxe6 is just as good.

17...c6 18.Nxe6

Threatens discovered check


18...Rd7 19.Nc7+ Kd8 20.Nxa8



Black to move

19...Kf8 20.Rxd6 Rxd6 21.Re1

20.Qxe6+ Kf8 21.d6 Re8 22.Qf5+

22.Qc4 is stronger. Whites material superiority and less vulnerable king makes the advantage overwhelming in any case.

22...Kg8 23.Ne4

White has a checkmate idea that Black does not find a way to stop.

Black to move

23...h6 offers more stubborn, albeit helpless defense.

24.Qe6+ Kh8

White to move

25.d7 is simple, but Lewis wants to execute a picturesque checkmate.


Black strikes back to win a pawn and check the king, but there is no follow up as Black's lacks sufficient force for a counterattack.

26.Kh2 Rae8 

Moves into the checkmate that Lewis hoped for in bringing up his knight.

White to move
27.Nf7+ Kg8

27...Rxf7 28.Qxe8+ Rf8 29.Qxf8#

 28.Nh6+ Kh8 29.Qg8+ Rxg8 30.Nf7# 1-0

*See Tom Standage, The Turk: The Life and Times of the Famous Eighteenth-Century Chess-Playing Machine (2002).

02 January 2022

Level 5

It is not easy to judge the difficulty level of a chess exercise. In a correspondence game fifteen years ago, I spent a full two hours or more finding the only non-losing move where there were multiple checkmate threats. Last October, I showed it to a friend at the Spokane Chess Club and he solved it in a few seconds.

Black to move

In Tactical Training (2021), Cyrus Lakdawala rates exercises on a scale of 1 to 5. He offers the suggestion that a mate in one illustrating the Dove Tail Mate should be classified as 0.5 because it is so easy (23). Nonetheless, several of my online students struggled with similar exercises in December (23). He states, "Level 3 is a problem that an 1800-rated player should solve without breaking too much of a sweat" (8), but I struggled with a couple of those this morning. "Levels 4.5 to 5 means that even a 2400-rated player may sweat to solve it" (9), but I solved one without much difficulty while eating breakfast this morning.

The Level 5 exercise that I solved this morning is the conclusion of a study by Vassily Smyslov published in New in Chess Magazine in 2000. I found the full study in Harold van der Heijden's Endgame Study Database.

It is number 132 in Tactical Training (114). Maybe you will do as well as I did.

White to move