mia analisi: Il
La lezione del GM Schwartzman: As you probably have noticed, this wasn't exactly one of the easiest puzzles.
Why? Well, let's just say that the right move doesn't look right, at least to start
with. But, before we get there, let's look through the position for a little while.
Who is better? Always the number one question, isn't it? But not necessarily the hardest one to answer in this case. As a matter of fact, I would say that white has pretty much all he could desire, except for a material advantage, that is. He has a pretty powerful rook on d1, controlling the entire 'd' file, without even the slightest competition from black's counterpart. He also has a knight on c5 that can't refrain from just laughing at the black knight on c7. I mean, just look at the two knights: white's can go to no less than 7 squares, and threatening a pawn, while black's can only go to two, and has to defend a weak pawn on top of that.
Moving on, we have to compare our bishop on f3 with black's knight on h4. Not too hard a comparison, right? On one side we have a very powerful bishop, who can go virtually anywhere on the board, particularly useful with pawns on both sides of the board. On the other side, you have a knight that is barely on the board. The only way back to reality is through f5, and that too is not really in, since a knight there doesn't have too many squares either...
Finally, there is the issue of the pawns. The pawn structures are in quite a contrast: black's pawns are quite a nice pair on the queen's side, while white has a nice passed pawn on c4, but a really weak one on a2. The reverse is true on the kingside: black's pawns suffer from a lack of advancement, and the e6 pawn is really weak, while white has a gorgeous pawn chain, of which both the 'e' and 'f' pawns are still mobile.
Overall, white thus has a superior position. But we still have not answered the question of what the next move should be. Or did we? After all, we just said that white's bishop can't even compare with the black knight. Which should answer the obvious question of whether we would like to trade the bishop for the knight: NO!!! So, if the black knight is threatening our bishop, wouldn't it be a natural reaction to move it away? Absolutely!
Well, the paragraph above is a very good example of logical thinking, which would hint in the direction of moving the bishop to one of the better available squares: g4, e4, c6. But, the same paragraph provides a good example of incomplete thinking. While we perfectly identified black's most obvious threat, and apparently, escaped it, we ignored an even more significant threat: e6-e5!
The truth is that while our bishop is indeed superior compared to black's knight, even more important is preserving black's weak pawn on e6. Not only is that a weak pawn, but it is what keeps all of black's pieces passive: the knight on c7 has to defend it, and the rook can't find an open file because of it. If we do indeed move our bishop, we would allow black to push the 'e' pawn, and suddenly get some counterplay, thanks to the pin of the 'f' pawn. As a matter of fact, a likely result of the move would be the creation of a weak pawn for us, on f4, once the pawns are traded there. What would that mean? Simple: three weak pawns for us (a2, c4, and f4), and one for him (a5) if you can even count that as weak.
In other words, we escape an evil, but fall into a worse one. Which is why, in terms of importance, black's threat of undermining our positional superiority with e6-e5 is much more significant, compared to just the trade of the light pieces. Consequently, preventing e6-e5 is our primary concern, and the move that does it like no other is the subtle 1.Nd7!
The idea is quite simple: by taking control of the e5 square, no one but the knight himself can get there. The result is also quite predictable: even if black does take our bishop, which he kind of has to in order to defend himself with a chance of success, we will take back with our king, and still preserve a clear superiority. Not only are our knight and rook much better than their black counterparts, but the king too suddenly becomes very active, with quick access to the center, which could soon become an important factor in the ensuing endgame. Obviously, black will not have an easy defense ahead of him...