White to play: 27 ?

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27 ♗d4xg7! wins material.

Position after 27 ♗d4xg7!

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Wow, Black was probably worried about a sacrifice on the f7-square but instead loses to a sacrifice on the g7-square.

White wins material because the White bishop is <TABOO>, as the Black g6-queen and g8-king will be <LINED UP> on the g-file for the <PIN> ♖f4-g4 if either Black royal piece takes the White g7-bishop.

27 ♗d4xg7! is a -TREMENDOUS- example of two important tactical principles:

1) Game Collection: King and queen are too valuable to defend (Nd--)

P.S. Looks like the Queen's range of piece point values is today between 9.75 to 8.8. Fischer valued the Queen at 9 points and that's the most frequently used value as far as I know. Of course, the value of a piece will fluctuate based on the positional or tactical situation(s) at different points in the game.>

If 27... Qb1+, then Black loses after 28. Kg2 Kxg7 29. Rfxf7+! Kh8 (29... Rxf7 30. Qxf7+ Kh6 31. Qg7+ Kh5 32. g4+ Kh4 33. Qf6+ Kxg4 34. Rg7+ ) 30. Rxf8+ Rxf8 (30... Bxf8 31. Qc3+ Kg8 32. Rxb1 ) 31. Qd4+ Rf6 32. Qxf6+ Kg8 33. Qg7#>

Looking a little deeper, it also weakens black's defense and initiates some mate threats. Of course, the bishop cannot be taken due to the queen-losing pin: Rg4.

2) Game Collection: King and queen on the same line always means PIN>

I considered Bxg7 briefly, but discarded it, as it didn't seem to be forcing enough, particularly for a "Very Easy." It is obvious that Black loses the Queen if he accepts the sacrifice, but it's not at all obvious that he has to accept it! As such, I kept trying to figure out something with Rxf7 and exploiting the resulting pin, but Black has f7 too well covered, there is not a way for White to make any real exploitation of the back rank after R(either)xf7 Rxf7, and as White's Bishop is on the dark squares, that won't work ...

http://www.k4it.de/index.php?topic=...

I'm aware of several internet table base endgame sites, but didn't have the one you gave. So thank you, and I've added it to my favorites.

I guess the advantage of having the table bases loaded into one's system would be not having to take the time to load and setup endgame positions on the internet. Also, if the tablebases did not affect a program's performance otherwise, it could I suppose enhance the performance of chess playing programs for analysis purposes.

What interests me is that I am not absolutely convinced that this is a win a White. It probably should be but Black certain did not put up much of a defense. Moving the Rook over to the queenside out of play was suicide. White can do nothing on the Queenside, so the only hope is to do something with the pawn majority on the Kingside. With 4-2 there he should be able to make something happen, but if Black had kept his Rooks home maybe doubling on the d-file and sticking one on the 6th rank he might have been able to hold out.

27.Bxg7
Damn, what a hard Monday. I had my original post up until I closed the window by accident and I'm got going to type it again. I think that <patzer2> shows all important side variations, and although declining the sac wins easier, Qb1+ with Kxg7 is defenitely outside the Monday scope (although I did spot Rfxf7+ winning at least a second pawn for the piece). I'm giving myself the points for seeing all other variations, but I think the puzzle was misjudged.

I know the feeling. I type any serious post in Word, and only then cut-and-paste into the keyhole they give you here at chessgames.com.

To help preserve this post against deletion, I will add that our hosts have set up an amazingly well-organized site.

Isn't a queen 8 points? At least that's what I read during my beginner chess course

Last time I checked, there's only one point given in chess, and that's to the victor. If a game is drawn, the players split the point.

This isn't just semantics, but an important part of understanding the value of chess pieces. We can talk about the chess pieces in relative terms.

For instance, a Queen and pawn are generally worth about as much as two rooks. The Queen is worth a little less than three minor pieces, depending on how well coordinated those pieces are.

The queen can stop most pawn chains as long as those chains are not advanced. Even the Queen needs the help of a second piece to deliver checkmate. I don't know how many "points" a Queen is worth. Even the value of a pawn changes over time and space!

I hope this pedantry finds a good home.

In the 10 point camp the argument is that a queen for two rook is generally considered an equal trade. Ergo, a queen is 5+5 or 10.

In the 9 point camp, it's pointed out that positions of a ♕♙ vs ♖♖ are generally drawn, therefore the Queen is not quite as good as two rooks. ♕♙♙ vs ♖♖ however is bad news for the rooks. Ergo, a queen is 9.

Pawn = 1.5
Knight = 3
Bishop = 3
Rook = 4.5
Queen = 8.5

Go Pawns!!!

Me see that me win with Knight vs. two Pawns against computer and me lose with three Pawns vs Rook! So me say:

Pawn = 1.125!!

Then you would need at least four Pawns to cope with a Rook, while three Pawns is usually worth slightly more than a Bishop/Knight.

Go Pawns!!!

Me have my own personality on ChessMaster9000 who says Pawns are worth 1.5 and Bishops 2.5!! And his strength of play is 100! And I will now see if he can cope with some strong opponents!