Computer plays Qb1??.  Black plays Rxf3.

White plays Nxf3 and black plays Qxf2#.

EDIT:  Just checked this with Rybka.  It is solid. 

http://www.chess.com/livechess/game.html?id=331014670

seems a nice mate in 3 at the end

NajdorfDefense, as explained several times already in this thread, I’m looking for beautiful, instructive, highly unambiguous puzzles. I’ve not started the thread to discuss existing TT problems, and I have written my personal requirements for puzzles in the first post.

ChristianSoldier, unfortunately there are alternative winning lines throughout the puzzle. It is however, a nice mate that I enjoyed working through.

Everling10, unfortunately there are already many puzzles using this classical sequence  in TT, so although it is unambiguous I’ve not added it, to avoid further duplication. As nate23 said, it is also a little artificial without more pieces. 

ClavierCavalier, alterations made. Interestingly even without the bishop Houdini gave black a slight advantage. 

nick4567, well done for recognizing the absence of alternative winning lines. Unfortunately I'm also looking for puzzles where the difference between the best and second best move at each step is ideally at least 2.5. White can also maintain equality with a different last move :

I hoped there would be a puzzle from the line if white tries to save his knight, but unfortunately there are many advantageous alternative moves.

Thankyou Metaknight251, I’ve chosen a different contination requiring a ‘look before you leap’ approach for black. 101st puzzle http://www.chess.com/tactics/server.html?id=417603

Thankyou vipera_raddei, I added an extra rook to remove alternative winning lines. 

102nd puzzle http://www.chess.com/tactics/server.html?id=457427

Asorski, black to move : c1=Q (-10) or Kc3 (-1.75) provide two advantageous lines. 

Katonas,

I hope I didn't take up too much of your time by asking a question in an attempt to understand the process, if so my sincerest apologies.

Nobody was starting a debate over old TTs, merely trying to clear up my own confusion about what you meant by 'ambiguous' in a forced mate scenario.

I'm sure your instructions are 100% crystal clear to the rest of thread.

Congrats on your fine work improving TT.

• http://live.chess.com/live?v=20120709#
• Move 24 begin

I was looking at my revised puzzle just now.  I just have to say I love the sounds!  When playing the right moves with the arrow buttons, it has a musical quality when clicked through at a steady tempo (like around MM 112).

Here is a composition of mine.

  Its quite complicated and has lots of varaitions (however, its black that makes the choices). Hopefully its instructive.

I have checked with engines in the past, but not specifically for the criteria of this thread :)

@blackadder-that is a cool one. however....  There are multiple ways for white to win.  Bxg7+ and Rxa7+ are winning.

@Metaknight251

Did you mean 3.Bxg7+ Kxg7 Rax7+ Kxa7 g6.... ?

if so, you are spot on, I checked and this works. Moreover it is arguably thematically better since the king ends up further away from the pawns!

This problem can be fixed by changing blacks response to Nxa7:

I dont like this line as much since I dont think it is as pretty. But nonetheless, the puzzle is more or less the same.

Hi Katanos

thanks for using the game, just want to know why the previous move Rcd8+ is not involved as puzzle move ?
102nd puzzle http://www.chess.com/tactics/server.html?id=457427

thanks again

artem

Hi all
Please take a look to this game 15 move for white  .
http://www.chess.com/echess/game.html?id=53165460 

Thanks 

My apolygies, there will be a delay before I can work on your submissions. I'll edit this post when normal services resume

A recent game of mine. Don't know whether there are more than one possible solutions, but I did a nice tactic and it could probably be used for TT:

http://www.chess.com/echess/game.html?id=55898714

@ Nwei  

Instead of 3. Rf3 White can play Qg6+ Kh8 Qxe8+ Kh7 Qh5+ Kg8 Qf7+ Kh7 Rf3.

Now technically this is worse since it takes more moves to mate. But Its hard to tell someone they got a puzzle "wrong" because they forced a rook capture and then proceeded to mate.

What do you mean when you say the next best move cannot be mate in more moves? I've done puzzles where I calculated a forced mate in, for example, 5 moves and then went for it and was incorrect because there was a different combination in 4 moves. Proved it with 2 engines.

Also, I have 2 live chess games with a number of tactical situations including a mate in 4 and mate in 3 (thanks to the tactics trainer I found both :)). How can I submit these games to be looked through for use in the tactics trainer?

this may be a little off topic but I need to know this in order to analyze games... how do I download and use an engine?

I disagree with 1... Kg7.  Since you're going to lose the queen anyways, I'd do this, which still gives black a material advantage.  It'll also be hard for white to stop those 2 king side pawns from promoting.  Maybe it'd be a better puzzle for black?