Yes, I think 18. Rc2 leads to a "black to move and mate in X" position

We can finally show how a position where white is lost looks like:
[d]3rr1k1/p2q1ppp/1pn3n1/6P1/3p2b1/P2Q1N2/1PRBPPBP/4R1K1 b - -
Black plays 18...Re6! and wins! 0-1
Moderator: Ras
Yes, I think 18. Rc2 leads to a "black to move and mate in X" position
Bf5 also wins after Rc2. White is holding on by a string in the current position.Ovyron wrote: ↑Sun Nov 10, 2019 10:57 pmYes, I think 18. Rc2 leads to a "black to move and mate in X" position18. Rcc1 is the only move that still holds the draw (except that one misstep and I'm toast, let's see if I don't trip.)
We can finally show how a position where white is lost looks like:
[d]3rr1k1/p2q1ppp/1pn3n1/6P1/3p2b1/P2Q1N2/1PRBPPBP/4R1K1 b - -
Black plays 18...Re6! and wins! 0-1
Yeah - a G-string.MikeB wrote: ↑Mon Nov 11, 2019 4:19 amBf5 also wins after Rc2. White is holding on by a string in the current position.Ovyron wrote: ↑Sun Nov 10, 2019 10:57 pmYes, I think 18. Rc2 leads to a "black to move and mate in X" position18. Rcc1 is the only move that still holds the draw (except that one misstep and I'm toast, let's see if I don't trip.)
We can finally show how a position where white is lost looks like:
[d]3rr1k1/p2q1ppp/1pn3n1/6P1/3p2b1/P2Q1N2/1PRBPPBP/4R1K1 b - -
Black plays 18...Re6! and wins! 0-1
I think I can defend Rc2 Bf5.
The conclusion is wrong.Ovyron wrote: ↑Mon Nov 11, 2019 6:48 amI think I can defend Rc2 Bf5.
Of course it'll all be moot if Harvey beats me.
But think about it, white MUST have a draw with best play, lest Harvey wouldn't care if I played Rc2 or Rcc1, because he'd know a line that beats both. The line that beats Rcc1 doesn't exist. A line that defends against any black attack exists. But can I find it?
You meant to say "the conclusion could be wrong", for the reasons you stated. But after I found 18. Rc2 Re6 it took me less than an hour to see black was winning, and I didn't need to solve it to a mate in X. My conclusion is only wrong if Harvey and me can't tell the difference between a lost position and one that isn't (say, the opening position is one that isn't). If we can, then on a given position, we know what move(s) save the game and which ones don't. To know that the conclusion is wrong, you'd need to know that the position is a mate in X yourself.
When I wrote the conclusion is wrong I meant that you cannot get conclusion B from knowledge A(not that B has to be wrong).Ovyron wrote: ↑Mon Nov 11, 2019 9:44 amYou meant to say "the conclusion could be wrong", for the reasons you stated. But after I found 18. Rc2 Re6 it took me less than an hour to see black was winning, and I didn't need to solve it to a mate in X. My conclusion is only wrong if Harvey and me can't tell the difference between a lost position and one that isn't (say, the opening position is one that isn't). If we can, then on a given position, we know what move(s) save the game and which ones don't. To know that the conclusion is wrong, you'd need to know that the position is a mate in X yourself.
Some things don't need proof to be true.
Following wrong premises (if I did) to reach the right conclusion doesn't mean the conclusion is wrong. It's like I try to find what's 2+2 and I follow a set of directions that are unrelated, and end subtracting 986 from 990 and getting 4. You could say what I did was nonsensical and unrelated about 2+2, but if I arrive at 4, then the conclusion is right, even if I don't know if 900-986 equals 2+2.Uri Blass wrote: ↑Mon Nov 11, 2019 10:54 amWhen I wrote the conclusion is wrong I meant that you cannot get conclusion B from knowledge A(not that B has to be wrong).
The position may be a draw with perfect play but you cannot get this conclusion from the fact that harvey did not find a win and there may be positions that there is a win but harvey is not sure if it is a win or a draw.
I can't play bullet chess, even in won positions I can't play fast enough to mate my opponents. I don't think my abilities to play bullet chess or your abilities to find the blunders you opponents played are relevant here.
I can. The opening position is draw with perfect play. The position after Rc2 is a mate in something in favor of black. This has nothing to do with solving chess because you don't need the solution to be able to reach right conclusions about positions.
As with other people on Talkchess you need 100% proof of something to believe it. As I said in the other post, some things can be true without proof. And if I make a statement that is true, it's a right conclusion and it doesn't matter how I got there, and it doesn't need proof. If I make the statement that a position is a mate in X for one side and it is, it is a right conclusion even if nobody would be able to prove it.Uri Blass wrote: ↑Mon Nov 11, 2019 10:54 amSuppose you play white and win and one move of black changed your estimate for expected result from 60% draw 40% win for white to
40% draw 60% win for white.
In this case it is not clear if this is the losing move or the losing move was earlier or maybe the losing move was later.
There are of course cases when you have 90% confidence that you win after a move but even in this case I prefer to be careful if it is not very close to 100% not to say that you win.