This was such an awesome idea from AllenC, and the mods approved, so I'll get this party started.
Posted this game in BBV, but I thought this position was really interesting and instructive.
Black to play has (I'm pretty sure) only one decisively winning line.
Answer with explanation:
Spoiler:
It's easy to bang your head against a wall trying to find a decisive checking combination that ends in mate or winning major material. In order to solve this, you have to find the right plan which involves:
1) Finding the right weak spot to attack.
2) Finding the right way to attack it.
Ultimately, the right weak spot is the the pawn on g2, and the right way to attack it is with the right piece coordination. There's a huge difference between a piece that is attacked by the queen first and the rook secondarily, vs. the other way around. And there's a huge difference between a piece that is defended by the king first and the queen secondarily vs. the other way around.
Getting there involves a fair bit of calculation.
1. ... Qh2+ forces 2. Kf2, the only legal move.
Now white's weakness on g2 is clear. It's "protected" twice, but since the first one is the king, it's vulnerable to a double attack. So now black must have the patience to play a move that isn't a check:
2. ... Rg6! Black threatens to attack that weakness in the optimal setup: Rook leads, queen supports, while white is trying to defend it with the worst setup, king first.
White's only move now is Ke1 (Qf3 loses the major exchange to Rf6, as does Rg1 after Qg3+/Kf1 Rf6+ and the queen is forced to step in the way).
3. Ke1 Rxg2
Black takes the pawn and threatens all kinds of seventh rank hijinks, but he gives up the initiative. If you are going to give up the initiative in a Q and R endgame, you better be really sure you can't lose because of it. Now it's white's turn to threaten bad things. Amazingly, white has no way to directly attack black's back rank weakness. His only threatening square is Qf3, threatening Qxf7+ and Qf8#.
4. Qf3
Black has to prevent the immediate mate threat, and also not allow white any other major progresses. h6 creates a luft square, but allows white to equalize by taking the pawn with Qxf7+, then threatening a perpetual with Qf5+. Black must block the check with Rg6 and he's gained nothing, and now white would have a clearly superior position. h5 is a little better, but still needlessly gives up a pawn and allows white a solid attack.
f6 prevents Qxf7+, but white gets several clear lines with which to check. But ultimately, black escapes with
4. ... f6
5. Qd5+ (or Qa8+ leads to the same thing eventually) Kf8
6. Qd8+ Kf7
7. Qd5+ Kg6
8. Qf5+ Kh6
and now white is out of safe checks and black is about to maraud him on the seventh rank and can force a trade of queens if he ever wants to. White's best possibility now is to play Rf2, allowing the trade of all remaining heavy pieces. Black enters a 6v5 king and pawn endgame with connected outside passers, and should win trivially. (Another option, which a computer will like less but might have more practical chances, is what white played in the game: Qf4+, which keeps the rooks on the board but leaves white just as lost down two pawns and having the less active rook).
I just thought that was a fascinating position. It shows a lot of key maneuvers in R+Q v R+Q endgames, as well as the need for raw, ruthless calculation in both seizing the initiative and knowing when you can afford to give it up.
As I see it, the problem with this thread is the OP: it's just too good and instructive! People are afraid to post without writing up a thesis. I'll lower the bar by posting a position and letting someone else figure it out.
I got a great position against a master strength player in a Chess with Friends game and decided to cash it in for the following position, having just queened with check:
Amazingly, black's incredible activity and dark square power give him excellent practical chances. What's your defensive plan?
A few moves prior...
White plays a7? thinking a queen is a queen is a queen and lazily not wanting to deal with the discovery after Bxd4...Qxd4. Of course it's easily defended against and if Black later blocks with Qa7 his position is just hopeless.
Spoiler:
The game ended (from the top position) 1.Qh6 Qd4 2.Rf1 e6 3.fe Rxe6 4.Kh1 Ne4 5.Be8? (Iphone Shredder can't decide on a move but seems to think White is better before this)
giving up the bishop for a tempo
...Ng6+ 6.Kh2 Nxf1 7.Qxf1 Qe5+ 8.g6 Qxg6+ 9.Kh1 Re8? (taking on e8 must give Black an edge but he was happy to get out alive) 10.Qb2+ f6 11.Qxf6 Kh6 1/2-1/2 with a perpetual.
The Qa8 and Ra1 are not participating so we need to get them back in the game. Once we manage to consolidate the game is over (should take like 5 moves from here?). Dark square control should automatically improve while doing this (too bad the other Q is not on c1, Qf8+ would work then). I'd start with 1.Qa6 or 1.Re1; gotta make sure there is no nasty surprises lurking somewhere, but something like 1.Qa6 Bc7 2.g3 e3 3.Re1 should win soon enough.
Summarizing,
What White wants to do:
- trade pieces
- activate the major pieces currently on the a-file
- consolidate
- get the dark squares under control
What Black wants to do:
- act quite fast
- get in a cheap shot
- create threats on the b8-h2 and a7-g1 diagonals
I've been playing over all of Fischer's games as white on chessgames.com (why? I dunno, just because). It's been a blast.
White played Bh4-g3, and black responded with e5-e4. The resulting tactic shouldn't be that hard to see, but I just found it beautiful. What an amazing example of piece coordination.
This is from Fischer-Weinstein at the 1960 US Championship in New York.
I wanted to play something simple like Bd7. But I was worried about Qh7+ Kf8/Bxh6 gxh6/Rxh6, which would leave us with this position:
Black's best move is ....
Spoiler:
Re2! Seriously? I almost couldn't believe the computer when it suggested that.
If white takes the queen, or even if he trades them off and then wins a rook with Qh8+, black's remaining pieces come up with a stunning forced mate.
1. ... Re2
2. Rxf6 Ne3+
3. Kf3 (forced, only other legal moves lead to Re1#) Bg4+
4. Ke4 (only legal move) Nxc2+
5. Kd3 (only legal move) Ne1#
When I saw that, I was all ...
Who here has the cojones to say they could have calculated *that* from the position above? (Some of you probably could, I know. I love and hate you at the same time).
Aren't you in dire straits anyways? The position looks a lot like a Marshall Attack where somehow white ended up with the attack. After Bd7, i want to make a Rxh6 sacrifice work, maybe with 2. h4 so that at the end of the 3. Qh7+ Kf8 4. Rxh6 gxh6 5. Bxh6+ Ke7 sequence we have 6. Bg5, winning the Q. To me it's not at all obvious how black defends against that.
Yes to dire straits, yes to Marshall Attack where white ended up with the attack, yes black has some awkward defensive work ahead of him and yes to not being able to find it
White should make the trade. He'll enter a bad v. good bishop scenario, but his potentially outside passed pawn and his queen's access to b6 should be decisive.
Here's a position I think is very instructive, except I don't have the answer. White to move, and what I want to know here is threefold:
1) Who is better?
2) Who benefits if rooks are traded?
3) If it's black, is giving up the file still bad enough that white has to trade?
I'd say Black is definitely better after ...Rxf1. If, however, it were White to move in that position then I like White because of the blockade on e5, weaker Black pawns in general and maybe a weaker Black king (not sure about that). I think it's actually better that White has some pawns on dark squares as they'll be easier to protect from Queen raids.
The above mostly assumes a Rook trade. After Re1 Bg5 might be annoying as 2.Qe2 loses g3 and the queenside, 2.Qb6 might be too dangerous and I'm not sure what's happening with 2.Qd4. It would take a lot of calculating. Black could also try ...Bf6, a Bishop trade, Rf6, and Qf7 but that might not work out either if White plays Bd6 -- but then maybe Black gets in ...e5. I'm going with the trade unless I study it all day in correspondence.
Edit: Just read Kyle's spoiler (maybe I should have done that as well?) and we're on the same page with Qb6 but I wouldn't even call White's bishop bad with the Queens on the board and where's the outside passed pawn?
Last edited by Allen C; 09-06-2011 at 04:43 PM.
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Two Plus Two
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