http://www.chess.com/echess/game.html?id=55572694

Thankyou Gopacklittlebro,

I removed the f6 knight to prevent alternative mate in 5 and mate in 6 solutions which would make the problem ambiguous. Unfortunately the problem would only be 1 move long because 2.Qxf1+ still leads to mate. 1 move problems are difficult for tactics trainer to give an appropriate rating. However mate was forced 1 move earlier if you take away white's f3 pawn (variation 1) providing a challenging puzzle, and black's defense blunder on move 17 provides some more puzzles.

variations :

56th puzzle http://www.chess.com/tactics/server.html?id=461789

The change in queenside pawn structure  prevents there from being any advantageous alternative to mating white.

another

57th puzzle http://www.chess.com/tactics/server.html?id=373945 

More variations. Black's correct 17th move should have been 17...Ne8!

59th puzzle http://www.chess.com/tactics/server.html?id=371733

17....Nf8?? as in the game allows

58th puzzle http://www.chess.com/tactics/server.html?id=450629

Help needed please with your approved problems.

Please add a link to the source game if available as a comment in tactics trainer under the problem.

If the problem is complex, and you are able, please also post some computer analysis as a comment. If you're able to do this for other people's problems, I'm sure they would be very grateful, as would I.

A perfect example would be :

Analysis by...(whatever engine you used)

1.  ... Nxd5

1. -+  (-2.69): 1...Nxd5 2.0-0 Nc7 3.Ng3 0-0 4.Ne4 Be6 5.c4 Be7 6.b4 Nd7 7.Bg5 Bxg5 8.Nxg5 Rad8 9.Bb3 Qc6 10.Ne4 f5 
2. +/=  (0.38): 1...Qd8 2.Bg5 Be6 3.Bxf6 gxf6 4.0-0 Bf8 5.c4 Nd7 6.Ng3 Bxd5 7.cxd5 Qb6 8.Rb1 
3. +/=  (0.45): 1...Qa5+ 2.b4 Qd8 3.Bg5 Be6 4.0-0 Nbd7 5.Nxf6+ Nxf6 6.Bxe6 fxe6 7.c4 0-0 8.Ng3 a5 9.Ne4 Be7 10.Bxf6 Bxf6 11.Re1 Bh4 12.g3 Bg5 13.Qg4 

Not only am I unable to do this with the Arena platform I use, it appears to be very time consuming to do this for every move.

Game: http://www.chess.com/livechess/game.html?id=326222434, but move the g pawn to g3.

White plays 22.Rxb7. Black to move...

I'm new to this, so please excuse my clumsiness. White plays 1. Ra3-Ra2.

Source game: Bouldoc-Chapa, Disneyland Open, Anaheim, CA 1983. 1. e4 c5 (1... d5 {[%emt 0:00:00]}) 2. Nf3 Nc6 3. d4

cxd4 4. Nxd4 Nf6 5. Nc3 e5 6. Ndb5 d6 7. Bg5 a6 8. Na3 b5 9. Bxf6 (9. Nd5 Be7)

9... gxf6 10. Nd5 f5 11. Bd3 Be6 12. Qh5 Bg7 13. O-O f4 14. c3 O-O 15. Rfd1 Ne7

16. Nxe7+ Qxe7 17. c4 b4 18. Nc2 a5 19. b3 Qd7 20. Qe2 Kh8 21. f3 Bf6 22. Qd2

Bd8 23. a3 Bb6+ 24. Kh1 bxa3 25. Rxa3 Rg8 26. Be2 Rad8 27. Ra2 Rxg2 28. Kxg2

Bh3+ 29. Kh1 Bg2+ 30. Kxg2 Rg8+ 31. Kh1 Qh3 0-1

jbzdarkid

I tried a few alternative moves for white instead of Rxb7 but black always seemed to have alternative winning moves, because black starts a piece up so adding a piece for black...

Allows an unambiguous puzzle.

60th puzzle http://www.chess.com/tactics/server.html?id=400331 

katonas, I know a nice tactic by White in Dvoretsky vs Bogomolov, Moscow, 1967, though I can't find the PGN anywhere. See if you can find it. 

The tactic goes (as I remember), 1. Rxd7 Kxd7 2. Qa7 Qxa7(forced or loses the Queen) 3. Bb5# 

StrategicPlay, 

Try BookOpenings > Search games > Advanced options and enter the players names and the yr for the game and let me know the link. If you can't find it I wouldn't be able to find it either.

chapablanca, thankyou for submitting such a lovely tactic. Its amazing to see  white's pieces hoovered up (see diagram). Unfortunately there are many winning alternative moves. 

If you send me a link to a game it will save you typing out all the moves. Using an engine to check a puzzle will often enable you to add/remove a few pieces to eliminate alternative winning lines. You're a better tactician than I, perhaps you can see a way of removing some of the alternative winning moves.

Powerlevel_9001, you have indeed created a fiendish problem that would win many a difficulty prize. However :

Ideally I'm looking for puzzles where each best move is +2.5 better than the next best move. This makes it more likely that the problem is conclusive, with a gain at the end of the puzzle that is easily explained. I don't mind being a bit flexible on the 2.5, but tactics trainer users have come to expect a significant difference, and perhaps ought to be warned that they should also be looking for smaller gains. However I think tactics trainer should be more true to real chess, and have many problems with as little as +1 gain eg.winning a single pawn to go from -0.5 to +0.5. There are so many simple pawn winning tactics that you just don't see in tactics trainer yet these are some of the most common tactics we see in games. I believe an open discussion on this might help (in a separate thread), with chess.com members perhaps even asking to see more of such problems.

At the moment this problem would rise to over 3000 and not be seen by many which would be a great shame after all your hard work. 

The first move is ideal for tactics trainer as it is the only way to save the game but 2.Nd7+ (+1.37) compared to 2.Nc6 (-0.10) isn't much of a difference.

Perhaps you could make some changes to get several short, probably still very challenging puzzles with greater gains over the next best moves.

katonas: 

I got it from a player's post at chessgames.com. 

Hi Katonas,

here's a few tactics. I've checked them with Houdini, hope they're OK.

White's 30th, http://www.chess.com/echess/game.html?id=29460748

Black's 15th, http://www.chess.com/echess/game.html?id=16869364

Black's 24th, http://www.chess.com/echess/game.html?id=29417982

Black's 34th, http://www.chess.com/echess/game.html?id=42089656

You may also want to conisider this game, http://www.chess.com/echess/game.html?id=25011688 from either move 50 or 52 for black. Not sure it's conclusive enough though.

Strategic play, I love the 2.Qh7 move!! wow. Unfortunately 1.Qf4 is as strong as 1.Rxd7. 2Qh7 has 2b4 (+8) as an alternative. 

Because 2.Qh7 is the beautiful move, its nice to focus a puzzle around this move. The hardest move of a puzzle should be the first. Adding two knights for black removes some ambiguous lines and enables...

A little gem. Thankyou.

61st puzzle http://www.chess.com/tactics/server.html?id=201999 

You're welcome, katonas. 

Are we allowed to post tactics from our own games? I posted one in the group forums but I feel not more than 3-4 people saw it. 

Should I post it in here? 

Puzzles from your own games are preferred, but please exclude alternative winning lines first with an engine. 

I have no idea how to insert your own games into Fritz 13..  

katonas, 

The new tactics trainer puzzle.. the one which I posted.. I saw that you gave it the tag 'Decoy / Deflection'. Maybe it should also have 'Mate in 2' and 'Queen Sacrifice'?

Powerlevel_9001 I'm still working on your puzzle but here is a gem that incorporates the great Qh1. I had to add a pawn on e7 to protect black's knight which if undefended creates a later ambiguous line.

62nd puzzle http://www.chess.com/tactics/server.html?id=283111 

Strategic play - I didn't give it a label. I only tend to label the easy ones!

I've never used Fritz but if you try clicking on the little PGN box next to a game on chess.com, save it onto your hard drive and try opening it with Fritz. 

edvinj, I haven't forgotten you, but I need a little time to do all that homework.