Black's undermining operations are yielding dividends. White's centre is starting to look ragged, and his bishops are going to disappear. Meanwhile, Black's bishop pair already look to have some interesting diagonals opening up...

13...Nxe3 looks playable, to me: 14.Qxh8(!?) Nxc2+ 15.Kd2 Nxa1 16.Ne2 Be6 17.Rxa1 Rc8 ... with a level game. White would probably play 14.Qxe3, again with a roughly level game, but with (perhaps) a better articulated position.

Was White aiming for a cheapo?! 14...Nxb2?? 15.Qxb5.

(?) But suddenly this is not looking so good for Black. The stranded pawn at c6 looked as though Black could pick it up at leisure, and Black might have been right about that. But he really had, I think, to keep the knight out of d5 (14...e6!). Now Black gets into strife.

The reinforcements reach the far flung infiltrators.

Maybe Black ought to be dealing with the c-file incursion instead - something like 15...Rc8. Now Black's already compromised game falls apart.

17.Rb1 also looks pretty much winning. 17.Bd4(??) is a mistake that compromises White whole advantage.

Possibly 18...e5 is an improvement. If then 19.Bxa7(?) then ... Black breaks out with 19...d5! 20.exd5 Qe7, with an edge. White would keep possibly a marginal edge with 19.Be3, say.

In the same way in the other game black plays e5 attacking Bd4 followed by d5

A good 'development' - gets his king out of the way of White's reserves.