Calculation Training

1. Qh5+ g6 2. Nf6+ Bxf6 (Kf8 Qh6 is mate) 3. Nxg6. I'll do the rest soon

Pretty good analysis so far: "I'll do the rest soon" means the position will keep its secrets until then

Usually I wait roughly a week before I post the puzzle solution, as typically someone gets the solution within the first few days. However, since no one has yet to post a complete solution: I'll give everyone some more time with this one.  No rush, whenever several more members give some further feedback: then I'll post the solution around then.

I'm sure you already know what "calculation" means in chess @SorryImAnon. For those who aren't aware: calculation is the ability to visualize potential chess moves (ply), as a sequence, without actually playing them. It is the ability to picture, in your head, possible chess lines before deciding on playing that line or an alternative you calculate (candidate moves).

This ability is obviously a beneficial skill to have for a chess player, so this forum is an effort to create a place where chess.com members can refine this skill via forum participation, actively solving the puzzles and learning from the posts of stronger players herein.

You're welcome. The meaning of "calculation" here really is as simple as it sounds.

We have had several deleted posts/accounts, so this forum hasn't been too active in a while. However, the most recent position hasn't been adequately attempted yet so ... bump

Nope.

Any analysis, or insight, into the "7th official puzzle?" It isn't that challenging, but I'd like to hear the reasoning - not simply winning lines alone.

1.Qh5+ g6 2.Nf6+ Bxf6 3.Nxg6+( credit goes to AnthonyAtasanov until there ) Kf7 ( or white mates with Nxh8 and Qf7 ) 4.Ne5+! ( not Nxh8?? , it just help black with allowing king to go h8 and white cant win. Rook on h8 is ineffective anyway.) Ke6 (Ke7 is similar, Kg7 lose to Qf7 and Ng4 with mate ) 5.Qf7+ Kd6 ( 5...Kf5 lose to 6.g4+ Kf4 7.Qd5 and black can nbot prevent Qe4 mate) 6.Rd1+ Kc5 (6...Kxe5 7.Qd5+ Kf4 8.Re1 and black cant prevent mate threads from e4 and f3 . 8... Kg4 9.Qf3+ Kh4 10.Qh3# )(6...Ke4 transposes 6...Kxe5 after 7.Qd5+ Kf4 8.Qf3+ Kxe5 9.Qd5+)   7.Qxc4+ Kb6 8.Qb3+ Ka6 9.Qd3+! Kb6 ( 9...Ka5 10.Nc4+ Kb4 11.a3+ Ka4 12.Qc2+ Kb5 13.Rd5+ Ka6 14. Qa4+ with mate to follow ) 10.Nc4+ Kc5 11.Qd5+ Kb4 12.a3+ Kb3 13.Qd3+ Ka2  14.Qb1+ Kb3 15. Rd3+ Kxc4( Ka4 transposes other variation after Qc2 )  16.Qc2+ and mate follow with Rb3+ and queen checks .

uhh It took an hour to calculate this.Especially Qd3 is very hard to see.

Yes, very impressive @Spaceysmile 

I thought this position was interesting to say the least. The stem game actually went much more simply, but I realized the vast complexity that you correctly "solved." Since your annotations were so in-depth, I'll only add the less complicated line that was actually played and a small "improvement" I hinted earlier. It is impressive that you were able to navigate the complexity though; I am sure the next posted puzzle won't be nearly as time consuming

This puzzle reminds me (with 16...Kf7 never played in the game) of a famous chess quotation. 

"Half the variations which are calculated in a tournament game turn out to be completely superfluous. Unfortunately, no one knows in advance which half." - Jan Timman

Thank you for the invite. 

Simply leaving this short reply so I get noticed of new comments. I'll look over the material on this forum at length in future. 

Thank you @keSetoKaiba

I wish I'd discovered this thread earlier. Calculation is something I really need to work on and places to train the ability are rare. I have a suggestion. All the positions in this thread are forcing lines, easy to calculate. I suggest calculation exercises that involve candidate moves, unnatural moves that one wouldn't normally consider, a few moves into the line.

Some lines are more forcing than others; some are from games, some are compositions and so on. I intentionally wanted a variety of sources, so the solver isn't biased too much before assessing the puzzle. Example: A game from Mikhail Tal will stereotypically feature sacrificing material, so the solver may be "tipped off" into looking for sacrifices if they knew the game. Another example: If they knew that this game was played during the romantic era, then they may find the solution quicker if they are looking for "romantic" potential, rather than analytically assessing pawn structure and material count. 

I appreciate the suggestion and will perhaps include more "abstract" solutions than the "best" move, but I also want the "solution" to be clearly the best move - hands down, once looked at.

I still like the idea behind this forum, yet it has been a while since any new puzzles have been presented by me. Not the only factor, but a big part for this was lack of participation; I want this forum to feature quality over quantity, so naturally more puzzles will be posted when I believe there will be more members potentially active  @Chess4PK and some others have shown an interest, so here is the "8th Official Puzzle." 

Remember that these puzzles usually feature deep calculation and that a key idea of this thread is exchanging of ideas (view previous forum puzzles for details). Good luck with this beautiful puzzle. 

Mikhail Tal vs Hans-Joachim Hecht, October 6^th, 1962; Varna ol (Men) fin-A chess tournament, Varna, BUL, round 9

Taking a look at the board the first thing I noticed was double attack by the b5 pawn but there's a lot more going on. White is down a pawn but he has more than enough compensation in the bishop pair, better pawn structure and much better piece coordination. Black's king is also still in the centre.

Since most moves lose material it wasn't hard to decide on candidate moves. I spent some time trying Nd6+ but then I realized that loses material since the black queen can just take on d6. The only other promising move was Qc2.

After 1.Qc2 you truly start to see how bad black's position. Now Nd6+ is a threat, white threatens to take the knight on f6(and after that there's the threat of pinning the queen with Rfe1) and Bxg6 wins white back his pawn. I'm still looking for a move that addresses all of these threats but I haven't found any(I looked at 1...bxc4, 1...Bc8, 1....Nf4, 1...Kf8 and 1...Nxh4). The best I've found is Nxh4.

My analysis is missing some of the variations I looked at(just a high level view) but typing that will take a lot more time and I'm afraid I won't get any sleep.

Solid analysis. Get some sleep; the puzzle will still be here later  So far, you've hit upon several key points of this position.

1. Qxh7+ Kxh7

2. Nxf6+  Kh6 (because if Kh8 then Ng6#)

3. Neg4+ Kg5

4. h4+  Kf4

5. g3+  Kf3

6. Be2+ Kg2

7. Rh2+ Kg1

8. Kd2#

All moves are forcing in this line and irrefutable.

Nice going @tonyklemm. The "first official puzzle" was a tough one to solve. Lucky for you, the comments from everyone else should give you some "personal" thinking from other players. 

What are your thoughts on this current puzzle (8th one), or did you want to first attempt the others? I won't spoil them if you want to attempt these without checking the answers

Tbh, I didn't even realize this thread was 200+ comments deep until after I submitted rofl!! I'll take a look though