This sequence of moves usually appears in my games, so when I swap of two minor pieces for a rook, is it worth it?
It's bad to swap two minor pieces for a rook, just keep in mind that the dark squared bishop and the knight was obviously more active on the rook which is just sitting on f1-square.
Black is somewhat better because the rook is passive defending the pawn, the dark squared bishop and knight has more activity in the game and so it is not useful or favors black to exchange two pieces on a rook. But in these case, Black can do exchange it and push the passed pawns forward, but in most positions I still favors 2 minor pieces in the endgame.
How about this position
(post # 9)
Well look a the position like I was saying... if black makes that exchange all his remaining pieces are undeveloped while white will have 4 developed pieces. So that exchange is very bad.
This sequence of moves usually appears in my games, so when I swap of two minor pieces for a rook, is it worth it?
It's annoying because black can lock the center right afterwards and white has to reposition his minors... but the fact that I even want to lock the center (white is more developed and has the bishop pair) means black must be worse... because I don't see anything active for black to do after that. It may take a dozen moves or so, but white should be able to show he has an advantage there.
Really it's rarely a good trade in the middlegame, and here you're doing it right out of the opening.
If you realize that two pieces is better than one piece (even a rook), then you wouldn't trade them for f2. In addition you waste so much time that with any kind of skill white will gain an easy advantage.
There is no answer to such a question, as well as similar ones. Post a couple of positions instead.
!
Quite a wise man we have here.
Here my opponent blundered as he thought I was sacrificing two minor pieces, so it is quite useful postion to have.
So, what is that? Hardly one move, starting from 3...Qe7, makes any sense (both sides involved).
Thanks, it appeared in blitz chess (i min per move)
IM pfren, perhaps you could put a position then...
In the opening you absolutely do not take on f2 or f7 to exchange two pieces for rook and pawn. (Sacrifices for real attacking chances aside.) The minor pieces are just way more active.
Imagine an endgame where the rook is just clobbering the pawns on the 7th rank while the pieces cannot defend. Then, ok.
My general advice is: Be happy with the 2 pieces if your position is solid enough. If your pawns are loose while you have no attack it's a different story.
Wise words from Dutchday
Wise words from Dutchday
Heh, really?
If you bothered to read the comments posted you'd notice this has already been said a dozen times, and his post is far from the most detailed.
Wafflemaster, I am just complimenting him, you are also wise...
You're sweet 
lol
1Checkmate, 2Material, 3Force, 4Time, 5Space/Mobility. Order of importance. Checkmate is not within the search horizon for either side. To be precise you're trading a Bishop and Knight for a Rook and Pawn. So you're essentially equal on Material value alone.
However Look at the other factors of the trade: The Black Knight on g4 puts a Force of 1 on h6,f6,e5,e3,f2, and h2 The Black Bishop on c5 puts a Force of 1 on a7,b6,d4,e3,f2,a3,b4,d6,e7,&f8 Where as the White Pawn on f2 only puts a Force of one on e3 and g3, and the White Rook only puts a Force of one on f2, d1 and e1. Not a good trade.
Time? Without the trade Black has 3 minor pieced developed to White's 4, White is castled, and black is not. Just a little behind but its Black's move and he can develop a 4th piece or castle. WITH the trade, Black has ONE minor piece developed to White's 4. MUCH worse. Time says NO! (time also says you shouldn't have moved the g8 Knight twice)
Space/Mobility? Black has 47 moves availble to him prior to initiating the trade. White: 32 After the trade: Black 35, White 41. I'm not going to add up forces on each square to find out which side controls more squares pre-trade and post-trade, but you could. My intuition says white would gain ground.
Remember to compare to the other legal moves you could make that may give you better checkmate, material, force, time, or space/mobility. There's many better moves, and IN THIS situation, that trade is not justified. Now in the endgame or elsewhere the same criteria may yield different results. But at least I hope I've helped you see why that is a bad trade in your example.
Also on your first example, the position is NOT illegal, its black to move, he's in check and must get out, but white is not in check, I do not see anything "illegal" about the position.
If I recall correctly there are two dark squared bishops and no pawn could have promoted to them, thus, a position that cannot occur in a game and is therefore illegal.
personally, i think rooks are slightly overrated, and bishops are underrated. So I would much rather have a bishop and knight.