In Sicilian Dragon is it a good idea to exchange the Black g2 bishop for a rook?

Sorry for the mixup in the title... Of course, I meant the g7 bishop not the g2 bishop...  :)

It's a huge temptation to exchange the dark-square bishop for the a1 rook, but that weakens the dark squares around my king and I'm exchanging an active bishop for a passive rook... Is it really a good idea?

It's not a good idea to have a predetermined "yes" or "no" in your brain for this scenario. It depends on how strong an attack on the dark squares would be -- sometimes it's strong, others it's not as strong. Remember that in order for weak squares to be significant, pieces need to be able to easily take advantage of them. It is dangerous because like you said you are weak on the dark squares, so certainly think twice before doing it! You have to assess how easy it would be for your opponent to attack you -- could he establish his pieces on the h6 and f6 squares quickly? Or would it be awkward for him to maneuver towards them?

If you can survive, then it was a good idea to trade the active bishop for the passive rook, because the passive rook had more potential (ever see a rook in an endgame? For a castle, it's pretty hungry). So you may need to calculate a bit, but at the same time, just see what your hunch is and just go for it! You learn the most that way. The more experienced you are, the better that hunch becomes, and there is no better way to get a feel for the power of the dark squares than getting decimated on them by your opponent!

It does depend. Also, it works for white too, would he exchange a rook for his dark squared bishop? The downside is that the Dragon bishop will now be unchallenged. Here is a recent example of black's bishops winning that battle:

Thank you Elubas and mattattack99, that helped a lot! 

I can't understand how a 2376 plays the Dragon like that???

His opponent was a 2560.

It is not the losing, it is the judgement that he made. Especially against stronger player he should make better judgement. May be he is unfamiliar with that kind of positions??? I think the key feature of a master is to understand positions/patterns. You do or don't do something because you know it is winning or losing.

Lay off him, man. He's a lot better than you. He probably knew there were dangers, but just thought he could take a risk -- he's certainly not clueless about the concept of a positional exchange sacrifice.

I thought he was not familiar with the Dragon positions so I searched for his games. Here is another Dragon game that he played:

A more common sacrifice in the Sicilian Dragon is the R sac on the N at c3.
I do no understand why anyone would sac the strong Black B at g7 for the R at a1.
The squares surrounding the Black kingside position become very weak. White's
kingside attack becomes very strong.

Best Regards
DarthMusashi

I just don't get the point... what could your motivation possibly be for bashing someone who you would never beat...  it just sounds really arrogant and patronizing to me.

Here is a game he won:

As the general rule, black is ought to maintain his black-squared bishop while white has a queen in his disposal. 

In other normal circumstances, black's black-squared bishop can be safely traded with the opponent's rook. Well-settled is the maxim 'time belongs to the Sicilian', which means black has better chances in the endgame. "Early game is to white, end game is to black," they say. Considering this idea, it will be decisive to maintain a rook advantage since a rook is much more powerful than the bishop in the endgame.

All of a sudden this Priyadharshan guy is getting famous!

Somehow this thread moved from the exchange sacrifice to how good or bad this player is!

Although some of the replies given addressed the issue, in neither of the example games given was the black King bishop exchanged for a white rook. Wasn't that the OP's question? Elubas's answer was the best. You should not have a predetermined answer but will have to analyse the situation at that time regarding the black kings safety vs how soon you can bring about a R vs B endgame.

Well, a predetermined answer for this question, as I already stated, is don't exchange the fianchettoed bishop while the opponent queen is still in the board. That is the general rule.

Who's bashing who? If you don't get a point, yes you can ask...

I was asking a "question". I think it is still on-topic, because I couldn't really understand the original question (about Bg7xRa1?). But the OP is 1700+ so some reference about thematic Bishop sacrifice should do.

Like your own answer, the Bishop sacrifice should be part of a grand plan. What is the grand plan? I studied the Dragon and I thought I knew. But here I saw a 2370 player played the Dragon against (part of it is sacrificing the Bishop) what I thought as the grand plan.

So, am I missing something? OR he (the 2376) is??? If his rating is like yours, I will assume that he is missing something . That's why the question. Because he is supposed to be a much better player.

You are bashing him.

You say you were just asking a question. Well, questions are not always harmless; for example, "Why are you so stupid?"

If you were genuinely sincere about your question, you wouldn't have worded it in the way you did -- which was quite similar to my example question above. You wouldn't disrespect a master.

No, I didn't. The second post may be. Because my question was: my understanding is wrong OR his understanding is wrong. I searched his game to find out if he knew anything about the Dragon.

Even if the answer were he is wrong, how that can be a disrespect?

"Why are you so stupid" assumes that "you are stupid". But my question was "I can't understand how a 2376 plays the Dragon like that???" doesn't assume anything.