Most significant square(s). Yours?

For me, it is no contest. The f5 and c5 squares haunt me as both colors really. Strangely, not vise-versa with f4 and c4.

I do not know why, but a lot of the time, it appears to be a tell-tale sign of the health of the positions I get, whether its the control, or mobility through these squares.

What are some key or important squares do you see constantly emphasized in your games or even calculation? 

I am not asking what is the most important square in general. I am asking what square(s) tends to show the greatest significance in your games and calculation.

Well, I do not know. However, I will point out that your point total is, as of this post, 1 higher than your rating.

Good show!

The Sicilian focuses on the d4 square.

I've had a few games where everything revolved around c4. Other than that, it changes a lot.

d5, rather.

If you are asking for the squares that mysteriously appear to play a great role in my game (with no rational reason), I must admit I usually love planting a knight on f5/f4. But of course the most important squares are the central squares...

I guess whichever squares white focuses on in Queen's pawn with c4 as my second move always, and black in Sicilian and Queen's pawn game.

Beats me - I never thought about it this way. In general I would guess the 4 central sqs d4-d5-e4-e5 would be high up in my "favorite sqs" list, at least in the openings and to a somewhat lesser extent in middlegames.

i'm always after an attack on the castle so h7, g7

For me at least, one of the significant squares is the flight square.  Has your opponent made sure they have given their castled king a flight square? If not, they may well snatch defeat from the jaws of victory if this all important square is not attended to...

http://www.chess.com/forum/view/general/chess-experiment-how-much-does-three-pints-of-beer-impact-your-chess-ability

It's the square ... the big one, of which all the other ones are mere fragments.

I'd say Magnus Carlsen - He's such a square!

X8 with the white pieces.

X1 with the black pieces.

X equalling whichever file my passed pawn is on. A-H

the e5 square is important

In the initial position f2 and f7 are defended only by the King. In certain lines of the Sicilian, as black, I am very wary of sacrifices on f7 and e6.

Much will depend on what openings you play.

With white, I play the English. Naturally, d5 is often the focal point for my pieces. Not that it is always the game changer, or anything.

With black, I will play the Sicilian. The squares c4 and c3 often make the difference.

Theres always something major happening on d4.

Ive always had a saying "the bishop was made to be on g5".
Since in all the fun lines it is.

As white, I choose the QP. So it's always d5 getting my attention. I also play Bird's (stonewall or transposition to reversed budapest with f4), so e4 is usually key there.

As black... f5 and h7. I play almost exclusively the hippo now, so preventing white's f5 is key... or defending h7 if my monarch somehow comes into the line of fire. Oddly, I don't really fear Bh6xg7, nor the associated squares; they usually handle themselves in the systems I choose.

The center squares for me!

And thank you for giving away your weakness.