Meta-Strategy
The first strategy to get stronger at 9 × 9 Go is to get back to the basic: Understand the game objectives.
Beginners play a lot of bad moves, as they want to capture. Then, they learn to be a territorial player, trying to surround a larger total area of the board than the opponent. They are advised by introductory Go books that such thing is the object of Go. They play the game better, but almost always fail to beat strong players. They do not understand the objectives of Go. The so-called "objective", in orthodox learning materials, is NOT the sole object of the game.
In fact, the objectives of 9 × 9 Go are multiple:
- To surround larger territory
- To reduce the enemy's territory
- To survive
- To kill, preferrably not foreseen by the enemy
All moves should be made efficiently, without needless moves. The ultimate goal is a desire for victory: To have a positive final score (Bs > 0):
Bs = Bt + Ba + Wp + Wd - Wt - Wa -Bp - Bd - k
where, Bs is Black's net score after the last move; Bt is Black's territory—number of points surrounded by Black; Ba is number of alive black-stones on the board; Wp is white prisoners—number of white stones captured by Black; Wd is number of dead white stones on the board; Wt is White's territory—number of points surrounded by White; Wa is number of alive white-stones on the board; Bp is black prisoners—number of black stones captured by Black; Bd is number of dead black stones on the board; k is standard komi size (e.g., 7 points).
Hence, each move has its impact on the final score, and has some effects that are not intended, and often not even foreseen. You can control the game if you know what will be the actual consequence of each move.
That is possible if you know the true meaning behind each move of yours and the opponent's. A classic way to know it is to use intuition or experience from review of quality games—the games by top 9 dan professional Go players.
The better approach is to use experience from superhuman reviews, in which you can see how and why the top superhuman AI makes each move like that in actual superhuman-vs-human games. For example,
Problem 1. Why is Tengen, 1, the best first move?