Hedgehog system.
I suppose he continued with Nd7, Ne7, b6, g6, Bb7, Bg7?
Strange setup
Sort:
Thank you. Had heard of the Hedgehog system before, but never investigated it or encountered it.
What is Black's idea??? It seems very nonsensical to me. As if Black is just waiting for White to load up both barrels with all he's got and then fire away.
Like any other opening system that doesn't occupy the center, he waits for you to occupy it so that he can control it from afar and destroy your center later on and take over.
It's sometimes difficult to make inroads into his position, so that you may be tempted to attack at the wrong time or at the wrong part of the board.
The name's a bit wrong - that's actually a Hippopotamus setup. The Hedgehog formation is a lot more specific: link
You seem to be saying that it's a game in progress so we shouldn't really talk about it but I'll just say DO NOT underestimate it. Whatever you may think about it, in the hands of a skilled player you don't know what could happen. If he does want to reach a Hippo setup, it seems to be quite a strange move order though. It could be that he just doesn't know what he's doing. 
It is a game in progress, but things have become radically different now and there is no more "playing possum" on his part. Once that happened, I didn't hesitate to post in the forum. My curiosity was out of control!
For what it's worth, he either changed his mind part way through or was going for some kind of odd transposition because we're now in a fairly typical position that I have seen a number of times in my games.
Thanks to everyone for the comments. My main concern is in playing OTB tournaments... I don't want to get caught off guard with this kind of thing someday and have no clue what I'm up against.
Never seen anything like this before, and it's less an opening than just a way to set up the pieces... I am playing White and my opponent seems to care very little about the center or develpment. I cannot figure out what idea would bring about these decisions.
Is there a name for this???