Calculation Training

There seem to be multiple ways to win from this position, and the knight sac is definitely the sharpest, but it wasn't the first line I pondered, it was this one:

I find this line interesting because it almost purely positional.  There's no real tactical shots or threats.  White simplifies down and then locks in control of the board with Rc6.  Black's knight is trapped, and his bishop and rook have severely limited mobility, even after alleviating the defense of the pawn at d6 (which will be no small feat since black's king cannot reach the e file).  I'd consider this a runaway for white if I could see an easy way for white's king to walk over to a5 (and that's the power of this position, is that while white's pieces are holding down black's pieces, white's king is free to walk around, while black has to extricate himself and cannot just counter with his own king...you might even be able to force black into zugzwang here), but crossing the black bishop's diagonal while white's bishop is keeping the knight trapped is thorny.

I pondered why I would see this line first, and the answer is that I am the type of player that will trade down to a pawn up endgame that is slow but crushingly certain over calculating tactics 6-8 moves deep and hoping I didn't miss a counter shot 7 moves in.  If I see both, I will take the positional squeeze without a hint of real counterplay to worry about.  More satisfying, and less blunders.

I guess it depends on your definition of trapped.  From the final position I gave, black has no way to dislodge white's bishop, nor to bring the rook to the c file, nor does Rb7 Nxd6 work, nor can the black bishop affect the situation in any way.  The knight is trapped short of black wasting both material and time with the sole goal of getting it out, but black loses badly this way, so...I call it trapped.

If you would like to calculate a plausible extrication that is not losing in the process, I would definitely learn something new .

I agree that the knight sac is winning, and it's clearly the best move to win outright.  I just said I find this line (and the resulting analysis thereof) more interesting (and arguably instructional, perhaps).  

A piece that is trapping another piece (while also serving other useful functions as well, in this case) I would consider well placed, not trapped.  I would not consider a rook "trapped" if it was pinning a knight, either.

Pushing pawns on the kingside is not going to work here...white is free to lock it up tighter than a drum with f3 at any time chosen.  You can open the h file by pushing the g and h pawns and saccing one...but that isn't going to produce anything because you cannot bring black's rook to bear in any meaningful way.

I know this is off topic but...

If you want real kind of these things, go to my formus:guees the chees peice.

I might post another position sometime soon, but first I'll give a chance to others to respond to my "solution" in post #132. Did I cover it sufficiently? Did I leave out something crucial? Was the position too vague in calculation? etc. 

I thought this was a good position to share because the calculation is a different type than simply forcing moves in King hunts; the calculation was far more positional in nature. 

Yeah it seems good . I want to speak A bit More about opening ( I generally try to enter it at black ) , generally at Last years after 4.f3 , both c5 and Nc6 is played much More . After 5.e4 d5 , white cant take any advantage at both . Generally white switch to 5.a3 after Nc6 , Idk What white prefers after c5 but know 5.a3 is possible again .

Also , can You repost my question ? It seems it was ignored .

About puzzle , there is not much to discuss , only thing to be calculated is Nc6 before cxd4 fail to Nxe6 , so black has to take cxd4 and open c3 square for white Queen .

Yes , I was Asking for evaluation of 1...Qxc3+ .

Actually FEN wasnt specifying colour as I remember 

but It should be black to move here in case I miswrote FEN 

At The Game , Last move was Rxc3 ( taking bishop ) , so I am Pretty sure it is black to move 

Isn't Black crushing White already? ...Qxc3+?? just gives away the Queen after the obvious bxc3 right? I think Black just has to sit tight and convert the position into a win. As @DaddyReza noted, just move the Queen to another square: ...Qa6!? looks bad for White. However, other developing ideas such as ...Nc6 look good for Black too. My evaluation for Qxc3+ is that it is impatient and probably just a blunder (maybe I'm missing something? I don't know). 

Here are my thoughts on the position: 

Pawn structure - Black is much better. Black has two pawn islands and White has three. Plus, Black's "small island" is a deep pawn only two ranks from promotion (on b3). Compare this to White's pawns sitting far back on their 2nd or 3rd rank with the exception of the doubled h-pawns, but Black's King safely blocks the promotion square, so the advanced pawns are of little danger to Black. 

Piece activity - I like Black better here too. White's King is biding its time in the center (somewhat dangerous with Queens on the board, but perhaps okay if an endgame arises soon), but Black's King has an active role of stopping White's h-pawns from advancing/promoting. The open a-file is controlled by Black. True, White may gain control of the c-file, but I think the a-file has more penetration threats. Black can infiltrate on the a-file faster than White can on the c-file. I won't address every piece, but White's are clustered on the bottom right of the board, not doing much, but Black's are more active. 

I realize that my assessment is more positional in description, but I think White is already on the verge of being lost if not already; of course, Qxc3+?? just throws away the advantage. Additionally, I noted how White's King isn't ideally placed with Queens on the board. White wants a Queen trade and I'm sure White would ecstatic to get the Queen for only a Rook.

Can black Press for win after bxc3?If Yes , How , and Does it succeed ?

Can white Save theirselves from perpatual with Kc1-b2-b3 Route ? ( at bxc3 variation ) 

Can white play Kxc3 ? 

etc etc 

Also , If You think Qxc3 is bad What should black play ? You Said You didnt Like The move , but havent suggested an Alternative 

One thing I think that gets in the way is the notion that calculating and analyzing these positions among human beings (key point here) is all about finding the single fastest winning line like an engine would.  If I'm presented a position where I can either go into a tactical 12 move winning combination, or I can achieve a completely winning endgame in 3 moves by trading down...I'm taking the latter, because that is the option that is actually much more likely to occur in the vast majority of games I am playing, and so that is most useful skill to discuss and acquire.  How to make a plan in an even middlegame?  How to turn a bad pawn structure into something livable?  How to eke out more space in a cramped position?  That kind of stuff.

Honestly, I think that's the best value in this thread.  There's already a ton of sources of "find the tactical shot" to take on, but almost no threads that tackle issues like the ones listed above.  I actually think that's why you see chess.com piled to the rafters with 1500-ish blitz players that will never make it to CM/expert.

Are you referring to my post #147, or did someone else attempt to evaluate the ...Qxc3+ line? I gave my reasoning and alternatives for Black; maybe someone else posted and I missed it?

+1 This is why I hoped this forum would be beneficial. Few "puzzle" forums are not purely tactical in nature; it is nice to look at and discuss the other parts of chess too.

p.s. I may post the third "official position" for others to calculate, later today.

I was reserving DaddyReza's comment that was end of Last post of Last page 

It has been roughly one week since I posted the 2nd "official position" of this forum (The Opera House mate was just an example position, and the other puzzles posted, although perhaps useful, I won't count as "official" so I can distinguish the positions I posted). I'll now present the "3rd official position." Calculate/evaluate this endgame position. The first time I encountered this puzzle, I did not correctly solve it, but I came really close. I "correctly" calculated (in my head from the original position, without moving the pieces) about 80% of this puzzle, but I missed a nice idea towards the end; As always, I recommend at least 15 minutes to study this position, but I think I spent about half an hour when I first saw this position. For those that spend time on their own with this position, I think you'll be glad you had when you see that "solution." White to move.

This position was given by Alexandra Kosteniuk in her book "How I Became A Grandmaster at age 14" This position is from one of her games when she was younger, but she didn't correctly solve this position: however, hers was in a blitz game! Hopefully you spent at least 15 minutes on this position yourself, if you are reading this hidden text xD. 

I can't see anything but a draw. I'd be amazed if this is winning for either colour with accurate play.

White has to take the d pawn and race his b pawn up the board. Black vice versa with his f pawn. We can take other pawns off the board too, up to white, if he has time for Kxa4 then black also has time for Kxh4. In any case, all I see is draw.

Okay , Let's try that 

First thing to notice is black is pawn up 

Now , Let's look If passive defense works 

After black Kf5 , there are 3 different square white King can be in , f3 , e3 , g3 

At e3 , Kg4 wins , at f3 , d4 wins , at g3 Ke4 wins 

So We had to try our chance 

1.Kd4 Kf5 

and now We had two option , Kc5 and Kxd5 

At Kc5 , it is not bad If black take f4 , but Ke4! wins for black 

So Kxd5 is forced 

1.Kd4 Kf5 2.Kxd5

Now at here it Get complicated , Because black has 2 options , went for h pawn , and went for F pawn 

If black go F pawn : 1)Kxf4 2) K-move 3) f5 4)f4 5) f3 6) f2 7) f1V

If black go h - pawn : 1) Kg4 2) Kxh4 3)K-move 4) h4 5) h3 6)h2 7) h1 V 

White's plan : 1)Kc5 2)Kxb5 3) K-move 4) b5 5) b6 6) b7 7) b8 V

so after both sides promoted their pawns it is black's move 

Let's divide that possiblities two : black Queen on f1  and it is on h1 

a) it is on f1 : 

white King Will stay on one of c5 , c6 , a4 or a5 

black King Will stay one of e4 , e3 or g4 .

b) It is on h1 : 

white King stay on one of c5 , c4 , a4 , a5 , a6 

black King Will stay on one of g3 , g4 

TBH I am not sure If I can calculate More , but I cant see A way any sides forcing A favorable exchange , so it should be draw More likely . Best reply for white at that variation seems taking a4 , when I cant see black trading good way . Without it , I afraid black can find A win with maneouvring Queen b3 , but I see Nothing with it ..

At the risk of getting myself in trouble here again by not posting a full analysis. this seems like it would take a ton of time to solve, but I will mention my considerations on first analysis:

There's two mechanics of interest. 

1.  One has to do with the obvious Kd4 and the theoretical exchange of pawns, and the resulting race.  I would say that the solution requires white to capture the b pawn (before or after the d pawn, since white can remain "in the square" of the d pawn while capturing the b pawn), then pick up a tempo with some trick, since the race right now ends up with 2 queens without any seeming advantage.  It's even possible the solution leaves blacks d pawn alive for a good while.

2. If white's king can trap the black king in front of his h pawn (after black takes white's h pawn, of course) and hold the opposition, he gets to also block the f pawn for free.  This could clearly be part of a drawing mechanic, but I don't see any way to convert this into a win.

If there were some way to race to b5, and then make it back over in time to trap black using the second mechanic (which only requires white to reach the f file if timing works out, so therefore shorter), I would think that would be the line I am looking for.

If the solution is a race to queens and then slogging through 2 queens trying to force promotions while delaying the other, then I'm not even going to attempt that analysis .

Quite honestly , though, this looks completely drawn and I am only accepting there's a solution because you said there is one.