02 March 2018

Ten Seconds

What should White play? It is a blitz game; seconds matter.

White to move

26 February 2018


This past weekend was the 26th annual Collyer Memorial chess tournament. I have played most years, and have had my best and worst tournament results in this event. Twenty years ago, after my first date with my wife on the eve of the tournament, I lost every game and finished in last place. Round five in 1998 remains my only standard rated tournament loss to a player rated below 1200. In 2012, I won all four games--I have been taking a third round bye in every weekend tournament for the past ten years or so--and finished in second place.

Many years, the Collyer has been the tournament that gives me my greatest rating increase, but my terrible performance two years ago gave me my largest ever single event rating drop--70 points. This year, I won three and lost one, but all of my opponents were rated lower then me. My rating change was -1. I tied with four others for second place in A Class. The A Class winner is a former student who has surpassed me in the past two years.

On Saturday, I played well in the first game but was unfocused in round two and failed to thoroughly assess the consequences of my opponent's plan. He ended up with a clearly winning ending, which he played successfully. I played better on Sunday. The most complex position tactically occurred in round five against Loyd Willaford, who nearly always gives me a tough game, but now stands at seven losses and a draw against me in standard rated play. You might say that I've been lucky.

The critical position arose after Willaford's 17.Bf4

Black to move

Willaford,Loyd (1658) - Stripes,James (1833) [D05]
Collyer Memorial Spokane Valley (5), 25.02.2018

1.d4 Nf6 2.Nf3 e6 3.e3 c5 4.c3 d5 5.Bd3 Bd6

Perhaps the bishop does not belong on this square. The combination of this move and 8...b6 gave my opponent chances that I should not have facilitated.

6.0–0 0–0 7.Re1 Nbd7 8.Nbd2 b6

This move brought me some difficulties.

9.e4 dxe4 10.Nxe4 Be7

I considered and rejected 10...Nxe4 11.Bxe4 Rb8, but my database tells me the line has been played in three master games with an even score.

11.dxc5 Nxc5 12.Nxc5 Bxc5 13.Bg5 

Black to move


13...Bb7 appears in the database. My move does not.

14.Be3 Qc7 15.Nd4 Bb7 16.Qd2 

I started trying to calculate the tactical and positional possibilities thoroughly during the five minutes I spent on this position and the twelve minutes spent on the next.

16...Ng4 17.Bf4

see diagram above the game score


I think my move is best.

17...e5 is a nice fork, but after 18.Bg3, Black must see that the knight is safe due to the pin. With the knight on g4 without protection, is it wise to offer White an unprotected pawn to gang up on?


During my thinking, I considered the main line to be 18.Nb5 Bxf4 19.Nxc7 Bxd2 20.Re2 Rac8 21.Nb5 and then my bishop must retreat to f4 or g5. I was not sure I liked my position, and only during the post-mortum discovered that I would have been ahead a piece in this line.

18.Bxd6 Qxd6 19.g3 gave me some concern because of the threatened discovery on my queen.

I also looked at the moves that followed in the game all the way to the end, as well as some unplayed variations.

18...fxe6 19.Bxd6 Rxf2

White to move


I was satisfied that 20.Bxc7 Rxd2 was better for me because I overlooked 21.Bf1. My engine says the position is equal.

After the game, Loyd and I examined 20.Re2 and White came out better in the lines we considered. This was a line I did not foresee during the game.


This zwischenzug was the key to making 18...fxe6 work.

White to move

21.Qg3 Qc5+ 22.Kh1

22.Kf1 looks bad, but was better. 22...Rf8+ 23.Ke2. I did not calculate further because it appeared that the lines would be forcing enough and I should not be worse due to the vulnerability of White's king.

22...Nf2+ 23.Kg1 Nxd3+ 24.Kh1

I thought 24.Re3 was better, where I thought I would play 24...Nxb2.

24...Nxe1 25.Rxe1 Rf8 0–1

Loyd Willaford's graceful resignation a piece down ended this game within the limits of a miniature.

31 January 2018

Keep Forking

Last week and this, I've been using my time on the bus to solve a few tactics exercises on Chess.com. I have attempted more than one hundred, finding that my concentration on the bus is often less than optimal, especially on the small screen of my phone. This afternoon, I muffed several easy ones by moving too quickly and skipping an elementary step in calculation, then spent three and a half minutes on this one.

White to move

I found the solution, then got several more correct.

28 January 2018

Study Material

Chess Informant 134 contains an article by Ivan Ivanisevic on "The Art of Unequal Exchange" that has material suitable for chess players across a range of skill levels. An unplayed variaton in his first game fragment offers some positions highlighting fork threats.

Black to move

The game is Gurieli,N. -- Matveeva,S., Moscow 1986. In the game, White played 15.Kxh2 and Black won back the sacrificed queen. Ivanisevic suggests 15.Re1 Rxg2+ 16.Kf1, which leads to the position in the diagram above.

White's battery on the e-file appears menacing. But after 16...e5 17.Qxe5, Black draws with a perpetual that forces repetition. Alternatives give Black White's queen for a rook via a knight fork. Black's material advantage should prove decisive.

Ivanisevic begins his article with this position.

Black to move

Black played 10...Qxd4! Simple tactics allowed White to win the Black queen, but in the resulting position, White's queen and king proved vulnerable. To this game fragment, the author adds material from historic games and several played more recently.

There is a 1962 game where Rashid Nezhmetdinov's three minor pieces were superior to a queen and rook due to the enemy king's vulnerability. There is a 1994 blitz game between Garry Kasparov and Vladimir Kramnik. Among the other games are a nice queen sacrifice by Hou Yifan and another by Fabiano Caruana.

Ivanisevic also includes one of his own games, a game where engines have shown in the decades since the game was played that his opponent missed several chances for clear advantage. Such positions offer good training material for sitting at a board and struggling through the imbalances and plans without silicon assistance.

White to move

From Drasko,M. -- Ivanisevic,I, Pale 1997.

23 January 2018

On the Bus

During the bus ride from the college town where I am teaching a class this quarter back into the city where I park my car, I attempted fifteen tactics exercises yesterday. This is one of those that I failed.

Black to move (diagram upside down with Black on bottom)

It is exercise 660988 on Chess.com.

22 January 2018

Checkmate Data

It is commonplace to speak and write about checkmate patterns. Certain recurring checkmates happen over and over again in games no matter the skill level of the players. Of course, once players rise above a certain level, checkmates become rare due to resignation either due to a checkmate threat or one player gaining an overwhelming material advantage.

Do claims about checkmate patterns stand up to data from played games? It is a simple, albeit time consuming matter to examine every game in the database that ended in checkmate. It may be possible to name every pattern in these checkmates and then list them in order of frequency.

Running on my desktop, ChessBase was able to find every game in my largest database ending in checkmate in about one minute. As I prefer quality over quantity, my largest database is smaller than many others, containing a mere 5.9 million games.

In this database, 148,127 games end in checkmate.

The last piece to move was most often the queen, and presumably this piece was always giving the check that is checkmate in all of them. Queen moves account for 59% (87,894) of the games in this selection.

The rook is the last piece to move in 24% (35,473) of the games. Most often, the rook is likely giving check and mate. However, a rook move can produce a discovered check by bishop or queen.

A little more than 7% (10,990) of the games ending in checkmate involve a knight making the last move of the game. Some of these, no doubt will be discoveries, but it's a reasonable prediction that the knight is checking the enemy king in most of them.

A bishop moves to checkmate the opponent in 6% (8,898) of the games.

Pawn moves account for slightly more than 3% (4,847) of the games. It will be interesting to study how often the pawn itself delivers the decisive check.

King moves account for a mere 25 games. More than half of these are by castling, so a rook is giving checkmate. The king cannot deliver check, but it can cut off the escape of an enemy king.

For example, in this game between two youth players from 2005, White's king moved so as to check by the rook and cover one of the escape squares.

White to move

One of the games that ended with O-O# could have gone on two moves longer with better defense. The combination strikes me as instructive. It is from Suess -- Hurme 1969, a game played as part of team world championship qualifier.

White to move

13 January 2018

Beware the Horse

Where should the queen move?

White to move

This position caught my interest. It appears in "The Art of Unequal Exchange" by Ivan Ivanisevic in Chess Informant 134, which I received last week. This article is quite interesting and offers study material that promises to improve my game, as well as helping me develop some materials for teaching young players.