Lets play a game of Chess

[Morecoin Freeman]

This is my favorite topic on bitcointalk.

I love chess and I have been lurking this thread for a bit.

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[letsplayagame]

This is my favorite topic on bitcointalk.

I love chess and I have been lurking this thread for a bit.

I am glad to hear you are enjoying it.  There are many good sites to play chess online and study tactics. I will try to add some value by making comments about how to think about certain types of positions.  After our game I will be happy to help analyze it and share some of my thoughts.

[letsplayagame]

My head is spinning with the chess problem; my line of thought was similar to obscurebean's.

I will vote for Nc1 as well

b3 - 1 vote (Timelord2067)
Nc1 - 2 votes (XMRpromotions, jjacob)

The problem was not easy but after seeing the pattern (knight on e7 and checkmate on h file) this type of problem will become easier in the future. Obscurebean saw the correct concept but still needs to think more about the best move order (in case black sacrifices the queen to avoid checkmate).

After you understand the first problem, think about how the revised problem can lead to forced checkmate instead of a material sacrifice by black to prolong the game. How can the new piece (bishop on f4) help assist the white attack in a forcing manner that does not allow black the same defense as in the first puzzle?

Soon I may start posting chess problems on Twitter. My hope is that more chess players will become interested in bitcoin after being exposed to this thread.  So feel free to talk about bitcoin related issues here in addition to chess.

https://twitter.com/ChessBTC/status/652587629163233280

[languagehasmeaning]

b3 - 1 vote (Timelord2067)
Nc1 - 4 votes (XMRpromotions, jjacob, taras, languagehasmeaning)

[languagehasmeaning]

Puzzle solution  :    Ne7+  Kh8    Rxh7+  Nxh7    Bxc6  dxc6    Qxh7+  Kxh7    Kg2#  

Great work on finding the right idea but look closely at your move order for an even better option in case black decides to give up the queen to stop mate.

Below I made a slight modification of the chess problem to illustrate my point.  Checkmate can now be forced in 6 moves. Although the mating line is one move longer than the variation you gave in the original problem, there is greater clarity due to no ability of black to stop checkmate.



People who already saw your proposed solution of the original problem can still try to solve this one. The shortest forcing line will look slightly different.

In the original problem we should play Bxc6 before Rxh7+ so that if black sacrifices his queen to stop mate we can keep our rook!

Ne7+  Kh8 Bxc6  and if black does not sacrifice his queen then we can play Rxh7+ (or Qxh7+) and transpose to the mating line given by obscurebean. If he does sacrifice his queen then our material advantage will be greater because we have not played Rxh7+ yet.

In the revised problem we can play 1.Ne7+  Kh8 2.Qxh7+ (our rook on h3 is actually a better attacker than our queen on b1 after our next move) Nxh7 3.Be4 and black never gets a chance to sacrifice his queen after f5 4.Rxh7+ and 5.Kg2#  after g6 then 4.Bxg6 fxg6 5.Be5+ Rf6 6.Bxf6#  or 4.Bxg6 Kg7 5.Bxe5+ f6(or Nf6) 6.Rh7#

The revised problem took me a long time to figure out. Is it a coincidence that adding a Bishop to the starting position changed the problem the way it did or did you think of it beforehand but decided the first problem was better for some reason? I don't think I would ever be able to solve this if you did not tell us it was a forced mate in 6. When you said that I decided that for the f4 bishop to matter the e5 to h8 diagonal would need to be opened. Since our king still needs to move in some lines to deliver mate, Be4 instead of Bxc6 made since once I realized it would force g6 and not allow the black queen to be sacrificed to stop mate.

I actually found many ways to win in the revised problem. The hardest part for me was finding why 2.Qxh7+ would lead to a faster win that 2.Rxh7+ (easy win but longer than 6 moves).

[boolberry]

Updated voting

b3 - 1 vote (Timelord2067)
Nc1 - 5 votes (XMRpromotions, jjacob, taras, languagehasmeaning, boolberry)

I did not solve the last problem in time. Hopefully I get another chance soon:)

[lottery248]

Updated voting

b3 - 1 vote (Timelord2067)
Nc1 - 5 votes (XMRpromotions, jjacob, taras, languagehasmeaning, boolberry)

I did not solve the last problem in time. Hopefully I get another chance soon:)

Nc1

[boolberry]

Updated voting

b3 - 1 vote (Timelord2067)
Nc1 - 5 votes (XMRpromotions, jjacob, taras, languagehasmeaning, boolberry)

I did not solve the last problem in time. Hopefully I get another chance soon:)

Nc1

b3 - 1 vote (Timelord2067)
Nc1 - 6 votes (XMRpromotions, jjacob, taras, languagehasmeaning, boolberry, lottery248)

[letsplayagame]

The revised problem took me a long time to figure out. Is it a coincidence that adding a Bishop to the starting position changed the problem the way it did or did you think of it beforehand but decided the first problem was better for some reason?

I created the original problem first and only added the bishop on f4 to illustrate the point I was making in responding to ObscureBean. The idea was not difficult for me once I made the original problem. The bishop can prevent the kings escape as you discovered.

I like the first problem better because unlike many chess problems it makes you think about variations that are not forced. It also requires more accurate play because of the material imbalance. As I noted already move order had some importance even after the correct plan was identified.

The second problem is not ideal because the material situation allows white to win with imprecise play.  In the So vs Nakamura problem I chose among two positions in part for the same reason. In one position there were multiple winning moves including 29...Be3 (instead of 29...h3+) which was chosen. In the other position, precision starting with 31...Qxf2 was required to win. In that case I also presented the problem requiring more precision.

In creating a problem I start by imaging some pattern (Ne7 and checkmate on the h file in this case). Then I can add or subtract pieces to make things easier or more difficult. Some think it is fun to checkmate by moving the king which is why I added that possibility here.

[Timelord2067]

I believe Taras' vote has been overlooked...

(ten messages back - this is message 616 that was message 606)

24. Qd1

b3 - 1 vote (Timelord2067)

Qd1 - 1 vote Taras

Nc1 - 5 votes (XMRpromotions, jjacob, languagehasmeaning, boolberry, lottery248)

Not sure if that was accidental or not.

b3 - 1 vote (Timelord2067)
Nc1 - 4 votes (XMRpromotions, jjacob, taras, languagehasmeaning)

But it sure was sloppy...

[languagehasmeaning]

I believe Taras' vote has been overlooked...

(ten messages back - this is message 616 that was message 606)

24. Qd1

b3 - 1 vote (Timelord2067)

Qd1 - 1 vote Taras

Nc1 - 5 votes (XMRpromotions, jjacob, languagehasmeaning, boolberry, lottery248)

Not sure if that was accidental or not.

b3 - 1 vote (Timelord2067)
Nc1 - 4 votes (XMRpromotions, jjacob, taras, languagehasmeaning)

But it sure was sloppy...

It was sloppy not intentional. Not sure how I confused Nc1 with Qd1. They both end in 1 at least. Sorry Taras!  

Thanks for noticing my error Timelord2067!

[Timelord2067]

It was sloppy not intentional. Not sure how I confused Nc1 with Qd1. They both end in 1 at least. Sorry Taras!

Thanks for noticing my error Timelord2067!

All good thanks for your reply. (I just realised last move was Qd1 wasn't it? (been a long game)...

[Foxpup]

I believe Taras' vote has been overlooked...

(ten messages back - this is message 616 that was message 606)

24. Qd1

That was the previous move. The current move is move 25. I vote for Nc1. (b3 blunders away at least 2 pawns, by the way, which is why nobody's taking it seriously.)

b3 - 1 vote (Timelord2067)
Nc1 - 6 votes (XMRpromotions, jjacob, languagehasmeaning, boolberry, lottery248, Foxpup)

[Timelord2067]

I believe Taras' vote has been overlooked...

(ten messages back - this is message 616 that was message 606)

24. Qd1

That was the previous move. The current move is move 25. I vote for Nc1. (b3 blunders away at least 2 pawns, by the way, which is why nobody's taking it seriously.)

b3 - 1 vote (Timelord2067)
Nc1 - 6 votes (XMRpromotions, jjacob, languagehasmeaning, boolberry, lottery248, Foxpup)

Indeed?  Perhaps if you were to glance back over the last few pages of posts where we (well, you at least) are too afraid to move, lest we be taken, b3 is the lest likely to be taken.

Nc1 is a retreat move, not a defensive move which b3 is by pushing our opponent back slowly while keeping our established defense in place.

[Aman41126]

I am very interested in playing chess.No one can not beat me in chess among my colleagues.Chess also actives the nerves of the brain.So it is the beneficial game for mind also.

[ObscureBean]

Great work on finding the right idea but look closely at your move order for an even better option in case black decides to give up the queen to stop mate.

Doh! Sorry for being lazy I should've seen that    
I'm just curious, how would you assess the position that arise after Qxc6  bxc6 ( from the variation I suggested), I'm no longer very confident it's winning for white, white has given up 3 pieces for the queen and I'm wondering if I may be overestimating the usefulness of the passed pawn on the c file (after c7) and the knight on e7.  
I realize this is kind of off topic so it's totally fine if you would rather not get into it.

BTW ChessBTC is a great idea, you'll be able to reach a lot more people through Twitter  


EDIT -  Don't worry about the question above. When I first looked at the position after bxc6 I immediately concluded that white was winning without really exploring possible lines, based on the position alone it just felt like white should be winning. Then later when I looked at it again and saw that after c7 black could capture on d6 instead of moving the rook, I started second-guessing myself. I'd been working it out in my head up to that point but the position was just eating at me too much lol so I decided to switch on the engine. It turns out white indeed has a winning advantage 

[gotmilk_]

25. Nc1

I enjoy in those chess problems...  Thanks

[letsplayagame]

This problem was not created by me and is fairly well known.

Black to move. Checkmate in 2



Give everyone some time to think about it. Once you find the answer you will know you are right.

[letsplayagame]

Your move bitcointalk. You have the white pieces

The current position is updated below:

25.Nc1    c4

[actmyname]

This problem was not created by me and is fairly well known.

Black to move. Checkmate in 2

-imghere-

Give everyone some time to think about it. Once you find the answer you will know you are right.

Are you sure that for this puzzle it's not mate in 3? I can encode a solution in binary if you so choose. Not seeing clearly a way for it to be mate in 2.