A quote from Phildor above:
"uhm sorry but HELLO, you can always miss some defenses and "mate" the king by a miscalculation....."
"and mate by a miscalculation?" 🙂
If you know by the very title of the problem you are looking for a mate
then how can you miscalculate and find the mate?
The task is to find the mate.
You study the position looking for a checkmate.
You do not look for a win of a piece hoping to stumble upon the mate.
(That is how computers do it by using the brute force method.
They will look at thousands of positions and stumble upon the mate.
Humans, thankfully, do not 'think' like computers).
When you have found the idea you check your analysis.
If it's still a mate you have solved it.
There is no need to look at the solution. You are right.
You have mated the King - the game is over.
If you cannot find the mate.
Never look at the solution. Find it. The effort is well worth it and very beneficial.
I've no idea what this has to do with my mistrust of computer judgement/analysis.
If a box says it's a mate in 5 then I believe it.
If a box says White is 0.09 of a pawn better then I ignore it.
BLACK TO MOVE
SPOILER ALERT
1298 people tried to solve this problem, and a whole 525 of them played 1...Bd1+. Many people actually went on to comment about it, to claim it led to a shorter mate and the problem was wrong.
END OF SPOILER
This kind of thing happens all the time, especially for inexperienced players. Remember, there are books with hundreds of mate in 1 problems. All chess players were beginners and they do miss a LOT of stuff, just I like I did and still do, just like you did and still do.
and suppose you have a mate in 7, in a mind boggling situation. It's so very likely that many will find pseudo mates in such problems, especially in ones containing quiet first moves.
Originally posted by heinzkatWe're talking about the 1001 mates book. for the sacrifices book, either solutions or computer check goes without saying, no discussion material there. (I hope!)
All very nice but Reinfeld's 1001 winning chess sacrifices book doesn't have such problems
Originally posted by greenpawn34
(That is how computers do it by using the brute force method.
They will look at thousands of positions and stumble upon the mate.
White to move.
My computer took 5 seconds to find mate in 14. During this time, it analysed around 12600000 positions. Sounds a lot. But if it were to do nothing but stumble around using brute force then potentially a mate in 14 (27 ply) could require something like 10000000000000000000000000000000000000000 positions.
Yes, a computer will look at far more positions that a human but this doesn't mean it only finds mates by stumbling into them. The computer's search is guided by heuristics, iterative deepening, etc. Even if we'll never agree on how "clever" these things are while playing chess, maybe we can agree a little on how clever some of the programmers are?! 🙂
Originally posted by Varenkahow long does it take with mate search switched on? (so it'll be actually be looking for the mate and not just skipping branches left & right, hoping to stumble upon working continuations faster than pointless dead ends.)
[fen]4Qrk1/3P2pp/p7/1p1q4/3N2b1/6P1/PPP4P/2KR4[/fen]
White to move.
My computer took 5 seconds to find mate in 14. During this time, it analysed around 12600000 positions. Sounds a lot. But if it were to do nothing but stumble around using brute force then potentially a mate in 14 (27 ply) could require something like 10000000000000000000000000000 e playing chess, maybe we can agree a little on how clever some of the programmers are?! 🙂
edit: 10 minutes on 920 i7 with 6gb of ram so far, and it's not even near finding a clue.
edit: 21min and it has no idea. I'll just shut it off now...
Hi PP
I need to ask you to look back my first post in this thread.
"surely if you have solved the puzzle correctly then you are looking at a checkmate. "
If these 525+ bods who got your posted problem wrong had taken the time to set
up the problem on a board and play out their solution they would see it was not a checkmate.
(1...Rxd1 pins the Rook they intended to mate with).
I take it you (or them other bods) don't have much experience solving
mate problems using a full size set.
If you want to produce these ideas OTB then study OTB. You won't make
the same mistake as those 525+ bods did.
Yes I suppose it's nice to look at solutions to confirm you got it right but if you
are looking at a checkmate on your board then why bother.
If you are sitting on a bus do you have to get off every stop to look at the
number on the front to make sure you are sitting on the right bus.
No.
So start to trust yourself, have faith in your ability.
Are you solving these thing to become a better chess player or having solved it
do you still have doubts?
Totally agree if it is a non-mating combination your are asked to solve
then best to look to see if you have it right.
Non maters require the additional skill in judging the postion after the combo
has been played to see if there is a counter-combo, a sting in the tail.
One question you have to ask yourself in a non mating combo you are about to play
is. "Why has he allowed this?" , "What is the trap?"
Of course in Mating combo's you need not bother. If it's sound then the
game is over.
Hi Varenka
I would not look for a mate in 14 in that position nor I doubt would any other
OTB player during a game.
1.Qxf8+ wins, 1.Rf1 wins (allows Black a check).
That is my quick glance and I did not need to look at 12600000 positions to
come to that conclusion.
Yes agree the programmers are clever and if ever I need a mate in 14 from
a clear won postion I'll give them a call.
Originally posted by wormwoodWhy does that matter? I wasn't running an engine with "avoid mate" switched on. 😉 Top engines by default look for mate, even if it's combined with other heuristics.
how long does it take with mate search switched on?
What engine and settings did you use?
Originally posted by greenpawn34my point was to demonstrate how some trivial move can be missed by almost half of the players. if there are books containing hundreds of mate in ones out there and people actually buy them, I believe it's reasonable to expect some people to miss things like these while analyzing over the board.
Hi PP
I need to ask you to look back my first post in this thread.
"surely if you have solved the puzzle [b]correctly then you are looking at a checkmate. "
If these 525+ bods who got your posted problem wrong had taken the time to set
up the problem on a board and play out their solution they would see it was not a checkmate.
(1. ver and if ever I need a mate in 14 from
a clear won postion I'll give them a call.[/b]
I just can't find an example now, but as I mentioned, this is even more likely for long mate problems where quiet moves are involved. I'm sure you're aware not all mate problems are check!, defense, check!, capture, bam!: mate. In some there are subtle defensive maneuvers.
Originally posted by greenpawn34Please don't twist the point of my example position. It was nothing to do with winning from a won position but rather to counter your point that computer's stumble upon checkmate. And you make no attempt to support your initial claim, instead preferring to go off at some tangent.
Yes agree the programmers are clever and if ever I need a mate in 14 from
a clear won postion I'll give them a call.