Help understanding this position

I was doing the tactics trainer and got this problem:

Kh4 is the move that gives black a huge advantage, all other moves are draw according to stockfish. I don't understand why... is the only way to understand is to calculate a shit load of possible moves ahead or is there something in this position that i completely miss that screams "GO Kh4!!" to the trained eye? 

I think Kh4 is a good move  but Kg2 is better ..... what do u think ???
i think g5 will b lost but h3 can b promoted.

This is a catastroph situation. When you make the second best move, your eval score may change not just from 1.2 to 1.3 but e.g. from +12.0 to -55. General methods and principles count for nothing in a catastroph, it's all about precise calculation. The correct choice may be determined by who promotes first, who promotes with check, or who can hide his king for a fleeting moment. In open endgame positions these things can make a huge difference.

Of course, if you insist on a global approach, you can expect that ...Kh4 is better than ...Kg4 simply because the latter blocks your g-pawn but it will not help you discriminate ...Kh4 from ...Kg2. But why not try to calculate? Not all that hard to see that black promotes first in a running contest after ...Kh4 and you could trust the other variations to luck.

Thanks.

Hello!

You need both of your pawns to advance to win THIS endgame. Any other moves either losing h3 pawn, or your king is in the way of your pawn march. Thats why Kh4 is the best. White wants to do the same,(push c4) but he blundered an important tempo with that Rd3+. It's not a trivial endgame position. You should try to make some move without help, PLAYING with the engine. Sooner or later you will get it.

That's usually how it is in endgames with both sides racing their pawns down.

Nothing that screams it, no.

The general idea (of course) is to have the king escort the pawns. If Kg2 then the king might end up on f1 when both sides start pushing pawns. So, at a glance, first thing I'd be doing is comparing the pawn race with a king on f1 white rook on f2 vs a king on h4 white rook on d3.

Often enough it's good to have the king in front, and you only need to queen 1 pawn, so blocking 1 of them doesn't matter so much.

So I agree more with what you said first... that there isn't a principal, and the player needs to calculate.

"Kh4 is the move that gives black a huge advantage..."

Its the only move that allows black escape the constant checks.

Is it?

Their was no way i was going to cover ever possible scenario.  This was the first one that popped into my head.  Purely illustrative purposes.

Only kh4 and kg2 make sense. Other moves block pawns for no reason.

Now kg2 can be answered by some checks. Rd2+ Kf1 Rd1+ Ke2 and now white can play Rh1 and black has to play g4 to try to promote the pawn. This seriously slows the pawns down and the black king is not that close to the pawns. At that moment I would calculate Kh4 before continuing this line.

Now there are several lines, white can try Rd7 or Rd1 or Kc6, but black's king seems to be in a better spot to support the pawns. So without calculating everything this just looks better.

The first question black faces is "do I play for a win or a draw?" When you run SF for a few seconds, it gives you the answer but such may not be clear to the blackplayer at all without making calculations. If he believes a draw is a good result he may easily end up choosing ...Kg2 as it leads to repetition or a quick exhange of wR for bP simplifying the position. It shows that you really need to sample some lines to know what you should be aiming for and only then start looking for the best move to support that target. Max Euwe: "Oordeel en Plan" (Judgement and Plan).

The starting position looks like either a win for black or a draw. The h- and a-pawns are both two squares away from promotion and the g-pawn is one tempo ahead of the c-pawn. It turns out c4 instead of Rd3+ is a draw. One tempo more or less is important. Rd3+ misplaces the rook and the rook is no longer in a good spot to stop black's pawns. After Rd3+ black is some tempo ahead and it is clear he is the only one playing for a win. A move like Kh4 can't possible lose. It doesn't allow white to promote with check or something like that in some long line. So basically Kh4 is the best try to win, if you haven't calculated everything.