Wednesday, July 2, 2014

Beating Inferior Openings: 4.Bc4 in the Four Knights Revisited

In his July 2014 review of Or Cohen's A Vigorous Chess Opening Repertoire for Black (2013) Carsten Hansen criticizes this Petroff repertoire book for giving three pages to the Four Knights with 4.Bc4?!, which Hansen considers to be a line that "should have received little or no mention." As I have argued in my first posting on this opening, Hansen is simply wrong when it comes to amateur chess. Amateurs need to learn how to refute such lines, which they will see orders of magnitude more often than the latest theoretical lines played by titled players. More to the point are Hansen's other criticisms of Cohen's book, notably its excessive reliance on long lines of computer analysis and its lack of clarity on its intended audience. Cohen's coverage of the 4.Bc4?! variation of the Four Knights is appropriate for rank amateurs, but its long lines without verbal comment are hardly useful for them. Most amateurs below about 1900 USCF need, I humbly submit, analysis like that offered in this blog's coverage of this line: lots of verbal and visual explanation of the most basic issues in an opening.

Friday, June 20, 2014

Rook Endings 4: Rook Versus Two Isolated Pawns.

We considered the fascinated case of rook versus two connected pawns in the previous post in our rook endgame series. This time the focus is on the rook versus two isolated pawns ending. Let's get right to it.

Second Case: Rook Versus Two Isolated Pawns.

In most rook versus two isolated pawn positions the side with the pawns is defending. The further separated the pawns the more difficult it is for the player with the pawns. This is illustrated clearly by the fact that pawns separated by four or more files can't defeat a rook on the 8th rank.

Monday, June 16, 2014

Rook Endings 3: Rook Versus Two Connected Pawns.

Endings in which a rook faces two pawns are more common and difficult than rook versus single pawn endings. There are 420 games in my mega database from the beginning of 2013 through mid-June 2014 in which this ending is played for four or more moves. 57 or 13.6% of those 420 games did not reach the result expected by the tablebases (meaning that there was a result-changing error). Some of those errors were, as we shall, by very high rated players.

There are basically two types of rook versus two pawn endings:
  1. Where the pawns are connected.
  2. Where they are isolated.
We will cover the case of connected pawns in this post.

Sunday, June 15, 2014

Rook Endings 2: Rook Versus Pawn Continued

In a prior post we examined the key ideas in rook versus lone pawn endings. In this post we will look at some special and complicated cases of this ending. Specifically, we will be looking at the following:
  1. A non-trivial case where the side with the pawn is winning. 
  2. A case in which the rook is between the pawn and its queening square and the attacking king on the other side of the pawn.
  3. The special case of the rook pawn.

Friday, June 13, 2014

Rook Endings 1: Rook versus Pawn

Rook endings are among the most common endings and playing them well is one of the most important and subtle endgame skills. To improve my chess (and hopefully yours as well) I am beginning a series of blog postings on rook endings. We are going to begin with the most basic rook ending: rook versus a lone pawn. These seemingly simple endings can actually be quite tricky and are mishandled more often then you might expect. Since the beginning of 2012 through mid-May 2014, 523 games in Chessbase's mega database reached a rook versus pawn ending that was played out for four or move moves. 47 or 9.2% of those 523 games did not reach the result expected by the tablebases at the moment the rook versus pawn ending began. To be sure, many of the poorly handled endings were by weak players who made silly mistakes, but not all of them. Even grandmasters erred. Clearly, this endgame is not trivial. Its key ideas need to be mastered. They are the following:

Attacking ideas:

1. Cutting the enemy king off at his fourth rank.
2. Gaining or losing tempi with rook moves.
3. Avoiding stalemate.
4. Getting the king in the game.
5. Moving the king to the side of the pawn opposite the enemy king.

Defending ideas:

1. Shouldering away the enemy king.
2. Promoting to a knight.

Let's look at them one by one, and then we will examine a few cases in which more than one idea is used.

Thursday, June 5, 2014

Mate in 549!

Mate in 549 is the latest discovery of the position-crunching supercomputers that calculate tablebases. Tablebases are databases of chess endings that have calculated the optimal moves until a draw or checkmate results. They can be purchased to put on your personal computer. Chessbase, for example, sells a product called "Endgame Turbo" which gives you the solution to all endings with five or fewer pieces and some endings with six pieces on the board. The data for this comes on nine DVDs and occupy 43 gigabytes on your hard drive when fully installed. That may sound like a lot of memory, but the full six piece endgame tablebase requires 1,200 gigabytes. Don't want to pay or clutter your computer with chess moves? You can also plug positions into online tablebase tools to find the chess truth that you seek.

Recently, seven piece tablebases were calculated by a supercomputer at Moscow State University and occupy 130,000 gigabytes. Among the nuggets of chess knowledge uncovered was that the longest forced mate with seven or fewer piece on the board is in 549 moves. Want to try to solve it? The position is as follows:

White to Mate in 549

Can't visualize it to the end? Give up? The solution is here.

After seeing this, I can't help but conclude that chess will never be solved. No computer will every play it perfectly, and the royal game will never be exhausted.

Monday, June 2, 2014

Beating Inferior Openings: Meeting 4.Bc4 in the Four Knights (part II).

In the first part the Four Knights after 4.Bc4 Nxe4 5.Bxf7+ was analyzed. In all lines black is much better. The lines analyzed here start with 4.Bc4 Nxe4 5.Nxe4 d5 (fig 1), which forks white's pieces, regaining the lost material.

Fig 1. Position after 4.Bc4 Nxe4 5.Nxe4 d5.
What is the best way for white to give back the material?

In this position, white has a number of options, only one of which does not hand the opening advantage to black. The main moves are 6. Bxd5, 6.Bb5?, and 6.Bd3. Other moves are, of course, possible, but these are the most commonly played ones. Let's consider each of them.

Saturday, May 31, 2014

Beating Inferior Openings: The First Installment of an Occasional Series (Meeting 4.Bc4 in the Four Knights)

Cyrus Lakdawala writes in his book The Four Knights: Move by Move that black players who open with 1.e4 e5 2.Nf3 Nc6 are likely to be poorly versed in Four Knights theory because they encounter the Ruy Lopez (that begins with 3.Bb5) more often than the Four Knights that white invites with 3.Nc3. This is simply wrong!

To be more precise, although Lakdawala may be right for master-level games, he is wrong when it comes to rank amateurs (rated 2000 USCF and below). Amateurs often lack either the time or inclination to study opening theory in detail, and when they do it is often because they obsess about one system. (Just think of all the Najdorf and Dragon Sicilian fanatics.) They take shortcuts, and taking shortcuts means deviating early from main lines to cut down the amount of theory that you need to learn. The Four Knights is precisely such an opening. Instead of learning the reams of theory in the Ruy Lopez (not to mention the Petroff), you can just learn the Four Knights. Even better, you can focus your efforts on one variation such as the Scotch Four Knights, and your opening study problems are solved! I don't play the Ruy Lopez (at least not yet!). Instead, I play the Petroff, and in my last thirteen over the board USCF rated games that began 1.e4 e5 2.Nf3 Nf6 white only played the Petroff main nine continuations of 3.Ne5 and 3.d4 three times. White in two of the three games was a class A player, showing that perhaps real attention to opening theory begins in class A. 3.d4 was played only once, and I had seen it so infrequently that I had forgotten the opening theory and lost because of an error in the opening. Five of the thirteen games continued 3.Nc3, inviting a Four Knights, which I played. Four of the games continued with the modest 3.d3, and one continued with 3.Bc4, playing in the style of the Italian Game.

Friday, May 30, 2014

Real Over the Board Tactics

Chess problem books would have you believe that most over the board tactical challenges are about winning a piece of delivering checkmate. More often it is a question of winning a pawn (often with compensation for the opponent--those famous poisoned pawns) or achieving a slightly better position than one would otherwise have. In these cases evaluation is no less important than analysis. The following game ended early because my opponent disconnected, but on the last move I was faced with a difficult problem. What would you play in the following situation?

White to move...

I played 14. Bb2?! You can find the analysis and learn what the best move is here: sputnick 2081 - dp15 1789, 45 45 time control.

Taking Advantage of Blunders

When your opponent blunders and loses material, he often has compensation in the form of a gain of time or better piece placement. Consequently, it is important to be very accurate when attempting to reel in the point after gaining material. In the following game, my opponent blundered in the opening. After 1. e4 e5 2. Nf3 Nf6 3. Nc3 Nc6 4. Bb5 Nd4 5. Nxe5 Qe7 6. Nc4?? c6 7. Ba4 b5 8. d3 we reached the following position with black to move. How should black capture?

8...bxa4 or 8...bxc4, which is best?

I chose 8...bxa4 on the general grounds that the bishop seemed dangerous on the same diagonal as the king. This is wrong. Concrete analysis is needed. From that it is clear that the knight on c4 is a much more dangerous piece as it threatens to land on the weak d6 square. Further, after bxc4 it will take some work to get the bishop on a4 back in the game.

I won in the end, but a better opponent could have equalized as the following analysis shows: hypernova2-sputnick, 45 45 game on the ICC.

Lessons to learn:
  1. 1. Don't make decisions on general grounds alone; rely on concrete analysis instead.
  2. 2. Consolidating and winning after gaining material is not always easy; it requires work.

Wednesday, May 28, 2014

Responding to 1.d4 with the Nimzo Indian and Ragozin.

I am in the process of revamping my opening response to 1.d5. Currently my repertoire consists of the Nimzo Indian and Queen's Indian. I feel that I understand the common themes of the Nimzo very well and have scored accordingly, but the Queen's Indian remains hard for me to grasp. My results in it have not been great either. Since I don't see myself making progress with the Queen's Indian any time soon, I have decided to remove it from my repertoire. Since I want to keep  playing the Nimzo, I have devised a repertoire that combines the Nimzo with the Queen's Gambit Declined. Specifically, it starts as follows: 1.d4 Nf6 2.c4 e6. Now, if 3. Nc3, I play 3...Bb4 the characteristic move of the Nimzo. And if 3. Nf3, I play 3...d5 with the idea of playing a Ragozin variation of the Queen's Gambit Declined, if possible. It looks at the current stage of my research that white can force an exchange variation by playing 4.cxd4, but the exchange variation with Nf3 is generally considered less dangerous.

3...d5!? is coming!

My guess--but my readers can tell me if I am wrong--is that most amateurs who play 3. Nf3 are doing so because they wish to avoid the Nimzo. They probably don't expect to face a QGD after black starts with Nf6 and e6, so you will have them stumped. And, since few opening books cover the Ragozin variation, you might get them out of book very quickly. Of course, they could have figured out these move order issues, in which case the game will be a hard fight--but that is ok as well.

For my analysis of move orders click this link to my QGD-Ragozin-Nimzo Move Order Analysis.