PlatinumDragon:I have studied GO ratios and found a ratio that defines the lines of territory. This line divide the boards as so:
This is what I call territory line. It is different then the standard territory lines that other players are used to. The influence line is define as territory line + 1. Why is this line so special? This line is special because the player who wins control of this line takes over half of the board either on the inside or on the outside. Usually, the player wants to take the outside because of its higher value and easier defense. By taking the silver instead of the grass, the player takes a dominating position.
Square are influence. No space for territory, White cannot live.
There is enough space for territory in corner. White can live in corner.
Notice that the 9x9 board is like 5 5x5 boards.
at 3-3 may not be a good move, but it can totally take away the corner.
Notice That the 13x13 board is like 5 7x7 boards.
Notice that the 19x19 board is like 9 7x7 boards.
The trend here is to tenuki 10 more stones for every size up.
The First Line Territory are too small, and the game is about influence. The Second Line Territory is not really a valid territory line, as the second line is difficult. This is more about tactics with equal territory and influence. The higher ups are more toward territory development first but by using tenuki moves to get sente in most subareas.
Most standard Board Sizes are at the top of each "Line Territory".
5x5 or 6x6 for first. This is for capture go and probably Fuseki (game) tactics.
13x13 for second. This is for tactics and probably Fuseki (game) strategy.
19x19 or 20x20 for third. This is for strategy. Any size this or beyond is probably for Fuseki (game) operations.
27x27 for fourth and beyond. These are for operations.
Because 13x13 is large enough for strategy to occur, 9x9 is added. 9x9 is small enough that strategic moves cannot be played.
2009-08-01: The line of territory is calculated by a formula that takes the size of the board and find the line that takes have the board. With the 19x19 board, 2.78 covers half the board so the territory line becomes 3. This formula calculates the line so you don't have to count the points from the edge of the board until you reach half of the board. I call this line the territory line because you can cover more than half the board weather you take the inside or the outside from this line. The next line is called the line of influence, and these two lines are where most of the battles are initiated.
Here's my analogy: First, you know how to count, so you speculate addition. Second, you know how to add, so you speculate multiplication. Third, you know how to multiply, so you speculate exponentiation. Fourth, etc.
So in the same sense, there is skirmish, tactics, strategy, etc.