Breakthrough For Black in This Pawn Up Heavy Pieces Endgame

This is the position, and black is on the move:

White is a pawn down, has a weak backward pawn on d4 as well. Black would probably like to somehow use his passed pawn on c4 and move his majority on the queenside by either playing b4 directly or playing a5-b4 at certain point.

However, it seems to me that white can make this very difficult by sitting, and not allowing b4 without losing the pawn back. Is there a breakthrough here for black, or is this a draw with perfect play from both and this -2.5 is a bit misleading?

Qb6 followed by a5 and b4. What can white even do?

Looks like game over.

Thanks for the answer, first of all.

Qb6, then Rcd1 defending that pawn. If a5, then Qc3 for white in order to attack c4 in case black pushes b5. It seems to me that white can somehow hold, at least for now if he is not forthcoming.

If Qc3 then black can play Rc7 and push b4 anyway. White is stuck.

Yeah, but that relieves the pressure on d4, and white can move one of the rooks and play Rb1 or Rb2 (not sure if there is a difference between those 2).

Obviously, you are correct that white is stuck, but it seems that black needs a bit more to beat this passive defense by white.

I won this by the way, but only because white helped me.

White has also weak king. You can combine ideas of making a passed pawn on the queenside with attack against the king(queen invasion via long light-square diagonal). In a right moment you can push b4 even if it's a pawn sac.

True, the thought had crossed my mind during the game that this might be necessary.

Interesting however, that this position looks dead lost for white, passed pawn, plus a weak pawn for white, seemingly clear intention to push queenside pawns for black, and yet in practical terms, it is not quite simple, and perhaps black has to open a second front in order to win this.

Thank you for taking the time to look at this.

The plan that comes to my mind is to put the Q on c6, Rooks on d7, d8 , play g6, h5 (so Qh1+ is mate) then see how white defends.

Bill

(It would be cool if Kh8, Q-d8-g8-h7 were winning but I dont think it does).

Thank you for the ideas. It doesn't win right away, but perhaps such a patient play and small improvements could bear fruit in the long run. White is stuck and black probably doesn't need to rush. Perhaps that would be enough with best play from both.