Pawn Break classified as a Blunder; How come? What am I missing?

Hi everyone,

I just played a really nice game as black where I played pretty accurately even though I was uncomfortable after an early attack on my f-pawn (knight + bishop for a rook). At some point I found my position ready to open up so I wanted to do a pawn break. Afterwards I saw that this move was classified as a blunder. Unfortunately the computer cant really explain how come. Does any of you have an idea why this pawn break on the d-file is a bad move?

Happy to hear also alternative ways I couldve continued besides the pawn break through the center. Maybe via the f-file with a battery?

Btw, first post here!

Kind regards, Willem

Yeah, with the open f file and the a7 bishop, kingside play seems more natural there.

But there's really nothing really wrong with 16...d5 strategically. After 18...Rxd5 your control over d4 means you can keep the d3 pawn weak and you'll also have long lasting pressure on f2. Your e pawn is isolated, but it's firmly defended by the knight (white has no minor pieces).

But 16...d5 is bad for tactical reasons. White can play Qb3 (before or after capturing on d5) which will win some material. Without that black would be winning easily. In the game white played the bad move 19.c4 after which black is winning (and went on to win the game).

Short answer, you create an isolated pawn on e5. There are other concerns. 

Black played d6 and then d5. This means they moved the pawn twice. What if instead of d6, black played h6, g5, and then d5? Now black is not worried about retreating the king that took on f7, and white's bishop is closed in for the moment.

Another thing I see, minor, but with d6, d5, white can play Qb3 attacking the b7 pawn. With the h3 line things look scary if white attempts to do this. They first have to get the c3 knight out of the way.

Your move 16.d5 was well intentioned...you have prepared everything, nothing is threatened, it's time to break open the centre and bring your pieces to life right? But the analysis shows that there is one move for white which causes you some problems and that the best way was to make extra preparations. 17.Qb3 for white is awkward to meet...

Engine likes Ne7 instead, solidifying even further and actually after this it's quite difficult for white to find a useful move. Certainly all the potential counterplay with Qb3 is not on the table now. 

Don't be too concerned though, you played a good game and your d5 move was logical. Only here there was a specific move in reply which would have lost a lot of advantage.