What basic skill am I missing?

Hi,

I stumbled upon this position while reading "Art of attack in chess"

Now white has to move the king to not loose material. 

My problem is that I don't see it. I would have easily have protected with the bishop on d2 and lost (1. Bd2 Nxe3 2. Bxa5 Nxd1).

My question is: What type of tactic / skill do I have to practice to see this in my own games? 

 While considering your defence to the check on your king , you should always ask what role is currently being played by any piece you are considering to use to block the check.

In this case the bishop was also defending the knight, but cannot do that after you use him to block the check.

Perhaps you would dismiss this as unimportant, because the bishop move would also threaten the black queen. But a deeper analysis of the situation would have shown that moving the bishop leads to a loss of a piece.

There is no short cut to considering all moves.

It sounds to me like you have a mental model of chess which treats pieces and positional motifs as static entities rather than dynamic forces.

E.g. you saw that the Bc1 is currently defending the Ne3, and just 'parked' this idea as a 'fact' which remains the case regardless of anything else that's going on. Try to remember that chess is a process and the game is in a constant state of flux.

It's a common oversight, you block and hit the queen, therefore the queen must move away. But sometimes there is another move like here which cuts across your plans. If Nxd3 did not also attack your queen it would be ok. So be sure to double check that you are not missing something basically, even if it seems your opponents reply is forced.

A good way to see things like this is to always keep in mind the connection between the positions of your and your opponent's pieces. For example, the first thing I see looking at this position is white's king e1 and rook a1 being a potential target for N-b4-c2 ideas. Similarly, when I look at the e3 knight, I see that it opposes the black knight and, in turn, looks at the white queen; if it were taken, the queen would be in danger, so you should keep the Nxe3 idea in mind no matter what move you make.

The only answer is practice, plus probably solving tactical puzzles to improve your intuition. When you've played a lot of games and gone through a lot of difficult puzzles, you start seeing things without even looking deeply into the position. What do we see here? White king is at the center, with the f2 pawn gone and the e3 square vulnerable; very common situation in games. The knight on e3 is only protected by the c1 bishop, and since the a5-e1 diagonal is exposed and some piece may have to block the queen check on d2, the knight might end up hanging. You start seeing these things with experience, because you encounter them in your and other games and puzzles over and over and they remain in your subconscious memory.

I definitly thought "he won't take my knight because then I will take his queen". End of thought process. As Strangemover points out, I didn't consider that the knight takes white queen next, which makes all the difference.

MayCaesar's point on seeing "the connections between the pieces in the position" is something I'm striving for, which I find as difficult as protecting pieces with tactics...

What I find most dificult is to learn the subconscious process all strong players have to ALWAYS see un-/barely protected pieces, (nearly) trapped pieces, new lines of attack, check/captures/threats, tactic patterns, connections in position etc. on every move for both sides.

Training this subconscious skill is what I find most challenging at the moment. So I do tactics and have started to play 30|0 games (used to to do 3d pr. move games, but an IM said it was a wate of time). I count my worst mistakes to work methodically on improving my worst areas. Seems like I have a lot of work ahead, but for some reason it's very addictive and fun :-)

Also after Qd2 white loses to the same pin and the fact that black can ( doorslaan op g2 ) as we say it in Dutch. Take through on g2  ( and with a check too! ) Also in that case you lose a piece with white.

(1. Bd2 Nxe3 2. Bxa5 Nxd1) - The threat black imposes (in my book) is called removing the defender. Like @Lagomorph said "you should always ask what role is currently being played by any piece". 
In this case your bishop is the defender of the knight on e3. So if black can find a way to exchange, block, pin ect. there can be tactics. I see you are a diamond member so stick with the tactics trainer, chess is 99% tactics! 

The better you get at chess, the more your chess sense starts to kick in.  You begin to recognize when tactics are possible or when the position becomes critical.  In this case, Black has most of his pieces developed (with the Knight on d5 excellent), has castled and the position is fairly open; in contrast, White has only three pieces in play (with the Knight on e3 awkwardly placed), his King is in the centre and the f-pawn has moved prematurely.  All of this suggests White should be in trouble.

You know how solving tactical puzzles is usually easier than a real game?  Most of that is because you KNOW there is a tactic hidden there somewhere.  Well, in the above position, you might not know there is a tactic, but there is a very good chance, and that gives you reason to look hard at moves that might initially look bad (such as Qa5 -> Bd2), and to look beyond the obvious reply (Qa5, Bd2, but do I have to move my Queen?  Is there anything else?)

This intuition or chess sense mostly comes from experience, but you can study to develop it faster.  If you play games of great attackers, they often get to similar positions as you posted and then pull out that unexpected move, the one that starts the fireworks.  If you play through many such games, you’ll get a much better sense of when sacrifices and tactics may be possible, and that gives you a clue for when to look deeper into a position.

Hope that helps.  I recommend Alekhine’s books and games if you’re interested in studying what I described above.

good answer to an interesting question,

Thank u

(and to the OP, for this thread) 

If I was white and the position shown on post #1 arose, I'd probably play Kf2. It's probably a refutable move but it was just my first thought... get out of check and give added protection to the knight, and don't use the bishop or queen to block because that will hang the knight. A lot more to it though at my second glance. Nc2+ kinda sucks if someone tries to block

BobbyTalparov: Thank you! It's obvious I don't count the right way either. 

Better stop now before I get too much on my plate to improve :-) I really think chess.com could have more videos/articles/drills on correct thought process, but maybe that's just me...

Disagree with Bobby here, I think that's a superficial way of approaching the problem, because what you should be interested in is what's left on the board after the complications, not what leaves it during them.

I just try to envision the position in my head after the complications and evaluate it, especially regarding the relative powers of the remaining pieces and what influences they could have on the game from that point.