Answering student's question

Langeweg (IM) v Ivkov (GM) Wijk aan Zee 1972

Q: 
In this game White (an IM) has just won a pawn by playing 10.N x c6  winning a pawn in a Catalan opening which has gone badly for Black (a GM!). There appears to be no compensation for the Pawn for Black here. I wonder why Black (a GM) did not resign here. Instead the game carried on until move 93 before Black resigned (two Pawns down in a K +Rook +2P  vs K + Rook ending) when the Pawn was about to queen!

A:
 Nowadays Ba6 is considered as better instaed of Bb7 in this opening. Yes, it should be won theoretically, but well - there may be some small compensation for Black, like the hanging pawn on d4 and c4 is not so secure too, and he tried to use open files and heavy pieces against them. And the advantage convertion isn't that easy for White, and took many moves, and looks like White played technically well, and without a chances for opponent. Well, of course it is hard to play or hope for a win on a high level as Black there, but practical chances for a draw there still are, and he hoped that for example he will oppose that extra pawn with his activity or will get some theoretical ending with extra pawn not sufficient to be converted, like a Rook ending where extra pawns not always mean guaranteed win, or exchange of all pawns of opponent that there was no queening possible etc with the same objective. Advantage convertion in such technical positions is not always that easy including on a high level, that's why Black kept up playing there. Even the final position with the 2 side Pawns in the Rook ending is known to have some technical problems to be overcame to be converted for a win and has some well-known traps on this path, including stalemate ideas, even in case when seems that a lot of work is already done and the King of weaker side is driven to a corner. By the way, interesting example to be practiced against an engine and I can recommend to try it.

My public interactive study for beginners

I've jus made one of my private Lichess studies public, and also this is an interactive one. Hope the players who will solve it will have lots of fun☺

The title of the study is "Exercises on the themes of centre and pieces development for beginners", and is like a set of elementary exercises for the other public studies I published previously.

It can be accessed by this link -

https://lichess.org/study/vzLB5yP9

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Now my Dad, Master Candidate at chess, has got his own one -

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My new channel on Goodgame

I've just got a new channel on a famous Russian-speaking platform -

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Answering chess questions

Q:

With a positional sacrifice 1.Ncxd5,  if Black accepts the sacrifice by playing 1.......exd5  White can either play 2. e6+  but the e pawn will be lost later so 2.Nxd5 looks better followed by 3.Bc4 looks good for White. Is this correct?

A:

Here, if White to move,the both continuations can give a solid advantage to White. But the first one - with e6 - looks like more clear and convincing one. The decisive point is the win of the pawn on d5 with Knight from f4, after the exchange on d7. Thus White ends up with a clear extra pawn + save his positional pluses and have an easy-to-play position. As to line with Bc4, it is more risky to do on practice, and White still has to prove his advantage and to play very accurately further in order not to miss some counterplay and not to get his passed central pawns blockaded.

Answering student's question

Q:
In the game Balashov - Platonov (USSR Championships 1971) Black has just played 23........ Q(e7-d6).  
Could you explain the purpose of 23....Qd6 as it appears to leave his black pawn on e4 unguarded.
It is attacked three times and defended twice so White by playing 24. Bxe4 can trade his Rook for two Black minor pieces.
Shouldn't 23 ......Re8 be played first?

A:

Yes, as I understand, that here Black aimed to get some close to endgame position after the exchange of all the pieces, with strong passed  pawn d4. Similar to the case of advantage transformation - from one kind of advantage into other. Trying to provoke the exchange but to get smth other in exchange. And also the Bf5 in pair with the Q can be strong in attack against Bk King. That's why Black agrees to get it exchanged, even by cost of one of his passed pawns. For the pawns it may be still long to go, and white is threatening Qh5 somewhere. King safety was the first consideration,  since White also had still his play there.

Answering student's questions

 The position is from a game Pachman-Bronstein Prague 1946.

Q:

If  19.  f4   then 19.....h4!

The reply by White 20.gxh4 would be anti-positional for White.But how does Black then go about capturing the h pawn. Would  Black then play 21.....Bf6 ? In trying to capture the h4 pawn Black would take the pressure off d4.

A:

First of all, having sacrificed a pawn like this, the side not always hurries to take it back immediately on a following moves, it can be like a long-term sac, for example with intention to weaken that pawn and then it can be a long-term burden to opponent, which then can make his pieces to watch this pawn all the time and to be tied up with its defence, and in the meantime the side who made the sac can be active on any other part of board, having a superiority in forces and activity there. thus to defend this pawn all the time can be bad to opponent, and to give it back can also be not good. GMs often sac such pawns with composure and use positional advantage connected with it. But there is also one condition, when sacrificing it, that it is better that such pawn wasn't mobile then, because sometimes it can be possible to take and then to advance the pawn, like after Bf6 move that you considered W can do it. So it could be good to have N on f6 to prevent it from moving or smth like this, and in this case after the capture Bk has also to fight against this possibility as well. Well noted by you, that bf6 takes to many time to get this pawn back and can get a bit misplaced. Then Qd8 maneouvre followed by Qh4 can be good in this case, especially that White's K-side got weakened after this capture, along with f4 pawn move (like it was in some of your games, that the move f4 can be connecetd not always with initiative but also can weaken K-side sometimes). Thus Qd8 h5 Qf4 with double attack on f4 and h5.

Also it is very common to continue with attack in the centre after such a sac, and another alternative can be 1... Rxa1 2. Rxa1 Nce6 3. Nde2 Nxf4 and white is positionally broken, or 1... Rxa1 2. Rxa1 Nxb3, everything based on vulnerability of W's centre.