If the machine found no errors upon which to comment, a number of hypotheses suggest themselves: 1. Your game featured a number of minor inaccuracies that cumulatively led to a lost game; 2. You just got outplayed; 3. The Nimzovitch-Indian is a forced win for Black in all variations. Note that these hypotheses are not mutually exclusive. I am intrigued already.

4. the GK machine is terrible compared to real engines 3100+

I open d4 in my games as black is not used to this over e4 GK recently changed engines in 2019 this game is from 2015 and cplusplus11 has been offline here on GK for 4 months

id=jkarp has been taking online chess school and it's something hard to believe it's 2019 and with all of his learning his rating is slightly up. He knows more about chess theory than Ii do and I always enjoy playing games with him as he was my first GK friend!

The first 3 moves by white are what I'll usually try to make sometimes Nf3 is to protect d4 11-10-19 I agree with what I said to this day.

Just an observation Moving a piece so far out in an opening is not recommended by basic instruction. I just wondered what prompted such an early move.

she pins the N and is willing to take with it if necesarry

4...b6 is a very strong move.With this move Black equalizes easily i believe.

I like this move as it allows to fianchetto the B and castling can happen later

I'm far from your rating, or Fisher's ( , but I don't like this move uness I see the plan behind it. The disadvantages are: it does not unpin the Nc3. Black can now play Bb7, and white has to untangle his kingside and his lsb. f3-d4 can be a plan, thoug...

I've seen this before but Bd2 or the other Be2 followed by Nf3 are more natural moves which I tend to make followed by castling

This is the Romanishin-Psakhis Variation (the Fischer continues 5... Ba6, while 5... Bb7 and 5... Ne4 are also possible). Too recent for the references I have available, so I can't help you with the theory  

OK thanks anyway! Further info is here - www.chesspublishing.com

Black anticipates the center break in order to take advantage inmediately of the pinned N (before white can play a3), leaving the Bb7 move as a card to play when appropriate.

c4 also prevents b4 now, allowing black to keep the pin over the N. I don't understand why white just don't play Bd2 and it's over...

I also like Bd2 to break the pin

i believe this to be an slight inaccuracy. Giving Black a 'slight' initiative. In my opinion 7.Rb1 was more applicable to the needs of the position.

7.Rb1 does threaten b2-b4, but it can be met by Na6

I thought that 5...c5 was a rather bold strategic decision for the reason that the bishop fetches up rather awkwardly placed, it seems to me. As White I think I would at ways of arranging b2-b4. That it induces a further eccentric development (...Na6) might not be such a bad thing for White... +++++++ Another idea, for what it might be worth, was 7.Bd2, freeing the rearward knight. Opening the 'bend dexter' diagonal looked risky to me.

@jkarp: I think that 'support function' means that the knight is stuck to defending the other knight.

Well, this was the to-be-foreseen disadvantage of the Ne2. It's downsides are more than his support function to Nc3.

@jkarp: undermine means to weaken or destabilise.

@jkarp: observe that the White d-pawn is supported by the White c-pawn. Black's move ...b5 strikes at the supporting pawn. It has - or is intended to have - an effect similar to knocking out the pit props of a subterranean coal mine, causing it to collapse. Hence: 'undermining'. 'Exacerbate' means 'to make worse', or can even mean simply to irritate or annoy. One might say here that by undermining the d-pawn's supports, Black seeks to exacerbate the precariousness of that pawn's situation.

9.b3 would have been much better.

...and the GK engine doesn't question any of these moves? I think that the black's edge is already well visible. True is that white has ways to untangle itself (o-o and e4), but black is in position to build urgent to address pressure. White is in a hurry to castle, which solves most of his problems, so the pawn's sac is not a very high price to pay.

at this point keeping the extra pawn is not paramount.Black seeks moves that multiply the mobility of her pieces.And now she has a 'balcony' on b3 and d3. A slow accumulation of tiny advantages. Whereas if White had played 9.b3 instead he could respond to 9...bxc4 with 10.bxc4 and open the b-file for his heavy Pieces. If then 10...exd5,11.Bg2! restores equality.And the shoe is on the other foot.

Square control. Even temporary square control has a value.

I wonder if black could have done better with b4, cxb4, axb4, Bxb4, Ra4, Qb6...