What White has set ip here is a species of Maroczy Bind, the sort of thing I used to play by transposition from an English Opening. More often arising from a Sicilian Defence opening, it does impose a considerable clamp on Black's Q-side in particular, discouraging, for example, the thematic ...b5 break. The dark square weakness is the price White pays, and it becomes a matter of whether Black can exploit this.

An alternative, and more usual, plan is to develop the bishop at g7, forming a kind of Dragon Defence. This is known as the Gurgenidze System, in which Black has to exercise considerable patience, in my view..

Black is exercising quite a bit of pressure upon the dark squares in White's centre.

A little bit of pressure against White's c-pawn. But the move is really to free up the rooks. That the bishop stands in front of the e-pawn is no inconvenience as there are no immediate plans to move that pawn. Soon there will be a battle around the d5-square...

Shouldn't white take into serious consideration Rb1, to untangle his pieces "threatening" Be3?

Threatening a pin upon the e3-knight (...Bd4). This Knight also eyes the c5- and e5-squares as possible bases for further action. ++++++ Around here, both sides have to begin thinking about how the game will continue - that is, to form some kind of plan.

Quite a thematic move for White, and therefore no surprise for Black. Black has little option but to exchange, bearing in mind the potential for threats to c7 and e7.

Note that even were a Knight still standing at f6, it would be the bishop making this capture. White's hold on the light squares is very powerful - Black's LSB (light square Bishop) has not much future in such an environment. In a semi-closed position such as this, the knights will have more scope - look at the hold Black has upon the d4 and e5-squares. So Black is happy to trade bishop for knight, even though White seems to obtain even more strength in the centre.

I think exd4 is actually better

In general White would be expecting to carry out operations on the Q-side, the way this game has developed so far (and which has been my usual experience with the White side of this sort of game). For that reason, cxd5 is usually encountered, with White hoping to make use of the c-file. ++++++++++ Although I was expecting this recapture, I will look further into the alternative. In such a case, one plan for Black that immediately springs to mind is a minority attack based upon the rapid advance of the a- and b-pawns, in conjunction with heavy pieces doubling up on the c-file.

Actually I was anticipating I might have to exchange this N for the e2-Bishop, but from d4 it was exercising its influence over c2 and b3 as well. So I was going to be in no hurry to exchange until pushed. At this point I give Black an edge, but only a marginal one...

White looks really cramped to me... it has to do a very great effort to coordinate his pieces before black can strike.

At this point I hadn't anticipated the combination that was to lead to such an advantage for Black....

But after this move, the crossfire seemed to offer Black some very interesting possibilities. Was 15.b4 a mistake? I'm not really sure. Possibly, though, White might have been better off resolving some of the pressure along the a7-g1 diagonal - and played 15.Kh1. White's game doesn't look all that bad here, to my mind.

Black begins a close assault upon White's position by threatening to win a piece after ...f4. Note the latent 'Philidor's Legacy' motif that forms a backdrop to the situation. ++++++ I have just looked at the GK analysis and discover that a far better move was 15...Nc2! Quite why I passed this by, I can't think - I'm fairly sure I looked at it. It's possible I concluded that the text was better, for some reason. If so, I was mistaken. What that shows, though, was that 15.b4 was definitely a mistake, and 15.Kh1 ought to have been preferred.

Kh1 on high priority on the "to do list"...  . Rf2 could be interesting, too. But of course, if black plays Nc2, white has Qd3.

I think you are right. 16.Kh1 would just about have force Black to take at once what profit he could from the situation: 16.Kh1 Nxe2 17.Qxe2 fxe4 18.fxe4 Qd4. At this point, the threat to White's back rank means he can not save the e-pawn, but at least White would have been still in the fight.

Looking at the computer analysis (which I had intentionally not run prior to annotating), this is called a blunder and is probably the game losing move. It suggests 16. Bd3, which I see mitigates the problem with the king still being on g1, ...buys enough time for the king to move. I have looked at Bd3 but found some reason to rule it out. I believe what happened is that I missed the negatives associated with the move played, thinking it was better.

From here on in White faces an impossible defensive task: his centre under heavy attack from all directions. I knew Black would win material here: it was merely a question of how much!