Playing Less than Optimal Openings

It seems to bit a thorny topic but for openings players seem to fall into 2 camps.

1) Playing the best opening possible trying to maintain and build an advantage.

2) Playing a sub-optimal opening for various reasons (they know it better, easier tactics, confuse opponent etc.).

I am squarely in camp 2, however I would like to hear what others think.

PS. I believe both points of view are valid, and from a super GM level and even World Champion level both have been practiced.

Yeah, I mean Grischuk played 1.f4 a few days ago in the Sinquefield Cup super tournament against So.

Openings are sort of like... the icing on the cake, the paint on the car. People focus on them too much. What matters is the middlegames you get -- how well you understand them and how well you can play them.

The main lines of classic openings have drawbacks too... namely your opponent is more likely to know those middlegames better. So I don't even, necessarily, make a distinction between "the best possible opening" and "sub-optimal" so long as we're not talking about objective garbage like the latvian or grob.

There are basically two types of openings: those you've studied well, whose middlegames you can handle, and those you can't.

What was it Portisch said?

The opening serves one purpose.  To get to a playable middlegame.

Although I'd also say that classical openings were discovered first because they're the most logical. There are plenty of lessons you can learn in those positions that apply to all of chess. So I think it's worth learning them, and playing them for a while, even if you ultimately don't make it your main opening.

Structures have a funny way of transposing into each other.

Just the other day I was looking at something completely unrelated to the king's gambit... like... a benoni or something. But on move 20 there was a certain structure on the kingside, and the engine was recommending these moves that seemed strange... then suddenly I realized, oh, of course, it's just like that idea from the king's gambit position.

So really, I think the more you know, the better, with the caveat that classical openings and main openings have more to teach you than stuff like 1.b4

Sub-optimal means giving your opponent easy equality (exchange lines, colle, london etc) or objectively a better game for some compensation (gambits, early e5 sicilians, budapest etc).

 Theres a quick example, a kind of reversed old indian. Definitely offbeat, but solid enough, just gives black easy equality.