We're going to have to revisit this problem from last week as the conversation about it got rather interesting, and you morons made some good points.

FEN: [rn3R2/pp4p1/2p3k1/8/8/2P1B3/PPP3PP/6K1 w - - 0 1]

The "official" solution to this problem is 1.Bf4! which secures the win of a piece. But AlaBAMA observed:

Sure, white can go BF4! and gain the knight, but only at the cost of swapping rooks. White will be left with a Bishop and King to try and advance his pawns for a queen (or another piece)...So, maybe I would keep that rook of mine pinning the knight and advance king side with my king and my bishop before I swapped.

This is a good point. And I've actually done this in games. That is, I managed to drop my rook on the back rank, pinning an undeveloped knight or bishop against a rook, which renders both useless. So tying up two of their pieces with only one of yours makes sense, and you can press your piece advantage elsewhere on the board.

And then Sayyid developed this a bit further with a suggestion that the best move is actually 1.g4!, after which Black

...being cornered with his knight pinned, will have to continue dinking around on the king side until he can, at best, trade a set of pawns to prevent white from just marching up pawns for the mate. White's already up material, so even trades while stopping black from developing his pieces are great.

AlaBAMA also said the trade would most likely involve him swapping out his rook, which he wanted to save for the endgame.

Then there was a back-and-forth about what the endgame was going to look like, and which version was preferable.

Based on this discussion, I went back and looked at the problem again. It wouldn't be the first time the "official" solution of a chess thread puzzle got cooked. But upon further consideration, I have come to the conclusion that the original solution, 1.Bf4!, is indeed the correct one. I will now explain why.

Last week, I said that in these "What is White's best move" problems, "best" could mean different things:

--wins the game
--achieves a draw
--wins material
--secures overwhelming positional superiority.

To this list, I should add one more:

--forces simplification to a won endgame.

Which is why I think the original solution is correct. Let's play it out:

1.Bf4!

So now White has two pieces leaning on the Knight. What can Black do?

1...b6

Not much. Anyone else see anything for Black?

2.Rxb8

Someone, I think it might have been Anon Y. Mous, pointed out that White shouldn't play Bxb8 because that will just leave his bishop pinned. This is correct. The exchange must be started with the Rook.

2...Rxb8

Black has no choice.

3.Bxb8 a6

OK, now let's look at the board:

FEN: [1B6/6p1/ppp3k1/8/8/2P5/PPP3PP/6K1 w - - 0 4]

As rickl noted:

After the exchange, White has a bishop and pawns and Black has only pawns. That's an overwhelming preponderance of material. It's an easy win for White.

In addition to the bishop, White has 2 more pawns. In terms of points, White is up by 5, a full Rook. Why would you *not* want this endgame? If I could force this position in a game I was playing, I'd do it and not give it a second thought. There is no need to prolong the game by holding on to your rook just so you can keep a couple of Black's pieces pinned. The simplification you can force will take pretty much all of Black's weapons away from him.

I tried to spell out last week what I meant by "best", but immediately I saw the necessity of adding another criterion to the list. Plus, the first one on the list was "wins the game", which really is a catch-all phrase which doesn't really tell you anything. So here is my revised list, ranked in order of preference:

1) Forced mate in 'x' moves
2) Simplification to a won endgame
3) Achieves a draw while seemingly in a 'lost' position
4-5) Obtains winning material advantage
4-5) Obtains winning positional advantage
6) Wins some material

If you have some others I missed, or think they should be ranked differently, let me know in the comments. You can think of these as tie-breaks in case you see more than one in the problem you're looking at. And I will be doing my best to include these kinds of "multi-faceted" puzzles. So just in case you see something, look harder, you might see something better.

But, there's always going to be a certain element of subjectivity in these "best" problems, which will result some interesting discussions on the chess thread.

Which, come to think of it, isn't a bad thing. And speaking of simplification...

Problem 2 - White To Play

Hint: Simplify to a won endgame

H/T to moron 'cesspit messiah', who sent me this puzzle:

FEN: [1k1r4/pP2q3/8/Q7/8/6bP/6P1/2R4K w - - 0 1]

This position from the book "Chess For Beginners" by I. A. Horowitz. It looks grim for White, but actually, he is able to pull his fat out of the fire. Find out how he can do it, and show your work.

Sexiest Chess Game Ever?

From the 1968 movie The Thomas Crown Affair. With Steve McQueen and Faye Dunaway.

Some comments:

1. I like that pre-Staunton chess set they're using, although it looks more decorative than utilitarian. I'm not sure what type it actually is. It looks something like this one, but not quite.

2. I'd forgotten that back in the day, Faye Dunaway was quite a hottie.

3. That little thing Dunaway does at around the 4:00 mark? I believe that's a "touch-move" and McQueen should've called it.

4. They didn't show the outcome of the game, but I think we can assume it ended in a mate.

Problem 3 - White To Play

Hint: 2 paths to a mate in 2, depending on Black's move. Find both.

FEN: [r2q3k/pp1b1Q1p/3p1bp1/5p2/2B5/1P5P/P1PP1PP1/4R1K1 w - - 0 1]

Problem 4 - White To Play

Hint: White can bring off a mate in 4 moves

FEN: [4qr1k/bp4p1/1n3rP1/p7/8/1P4K1/P7/4Q1R1 w - - 0 1]

Now you can use what you've learned to solve this very silly problem:

FEN: [4qrk1/6p1/5pP1/8/8/8/P7/KQRRRRRR w - - 0 1]

I realize there are, no doubt, other ways you can find for White to force a win, what with him having a bunch of extra rooks and all, but try to do it using the same technique used in the prior problem.

Endgame of the Week

FEN: [8/8/8/pPk5/P7/2K5/8/8 w - - 0 2]

Black has just played 1...Kc5. What does White need to do to win this game?

___________
Solutions Update:

Problem 1 - White To Play

When you look at this problem, you should note that the position is such that there are simply few, if any, legal moves on the board. In fact the only legal move on the board right now is:

1.axb5

Black's reply is also the only legal move on the board:

1...axb5

And so it goes:

2.a6 b4
3.cxb4 c3
4.b5 c2
5.b6 c1=Q
6.b7#

Problem 2 - White To Play

White is able to simplify to a won endgame:

1.Rc8+ Rxc8
2.Qxa7+ Kxa7
3.bxc8=N+!

Ha! Did you see that one coming?

3...Ka6
4.Nxe7

And now, thanks to the Nalimov Tablebase for 6-Piece Endgames, we know that this is a win for White. Black cannot stop the queening of at least one of the two remaining pawns.

Problem 3 - White To Play

White's first move is

1. Re8+

...to which Black has two responses, both of which cannot stop the mate in 2:

1...Qxe8
2.Qxf6#

-or-

1...Bxe8
2.Qg8#

Extra points if you found both solutions.

Problem 4 - White To Play

The thing to notice about this position is that the white pawn up there on g6 is like a knife stabbing Black right in the gut. Wouldn't it be great if you were playing White and could somehow get your queen over to the 'h' file and deliver a checkmate on h7? Well, as a matter of fact, you can:

1.Rh1+ Kg8
2.Rh8+ Kxh8
3.Qh1+ Kg8
4.Qh7# 1-0

This pattern of a open rook file and rook sac followed by queen checkmate is so common that it actually has a name, Damiano's Mate. It's named after the chess master who first wrote about it all the way back in 1512 (!)

So, this pattern of moving the rook over and then sacrificing it so the Queen has the opportunity to deliver the mate can be repeated if you have 2 rooks. Or even more rooks. So I composed that ridiculous 2nd problem just to show how it's done:

1.Rh8+ Kxh8
2.Rh1+ Kg8
3.Rh8+ Kxh8
4.Rh1+ Kg8
5.Rh8+ Kxh8
6.Rh1+

Yeah, I can do this all day, buttercup. And there's nothing you can do about it.

6...Kg8
7.Rh8+ Kxh8
8.Rh1+ Kg8
9.Rh8+ Kxh8
10.Rh1+ Kg8
11.Rh8+ Kxh8
12.Qh1+ Kg8
13.Qh7# 1-0

Endgame of the Week

White needs to be able to outflank Black, and force him away from the pawns. Black, of course, will try to stop any advance by White's king.

2.Kd3 Kd5
3.Ke3 Ke5
4.Kf3 Kd5

Black cannot reply 4... Kf5 here because then he'd be too far away to stop White's pawn on b5 from queening. 5. b6 wins the game.

5.Kf4 Kd6
6.Ke4 Ke6
7.Kd4 Kd6
8.Kc4 Kc7
9.Kd5

White can also win with 9.Kc5, but it's not as simple.

9... Kb6
10.Kd6 Kb7
11.Kc5 Kc7
12.b6+ Kb7
13.Kb5 Kb8
14.Kxa5 1-0

___________

Note: that cryptic line of letters and numbers you see underneath each board diagram is a representation of the position in what is known as "Forsyth-Edwards Notation", or F.E.N. It's actually readable by humans. Most computer applications nowadays can read FEN, so those of you who may want to study the position, you can copy the line of FEN and paste into your chess app and it should automatically recreate the position on its display board.

___________

So that about wraps it up for this week. Chess thread tips, suggestions, bribes, rumors, threats, and insults may be sent to my yahoo address: OregonMuse little-a-in-a-circle yahoo dott com.

posted by Open Blogger at 04:55 PM

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