A veteran single-digit kyu player at our club once told me, “I never review my games because if I win I don’t need it and if I lose I’m no longer interested.”
In the words of Luke Skywalker: “Amazing. Everything you just said was wrong.”
Of course you need to analyse your games to find your strategic and tactical mistakes, or your mistaken way of looking at a position. But you would be amiss to only analyse your lost games. The one who loses is the one who made the final mistake, or the most decisive mistake. The winner made almost as many mistakes.
In other words, you did not win because you played perfectly, you won because the opponent played even worse than you.
If you believe that you played well in your won games, you may be reinforcing bad habits that won’t work against a stronger player, thereby hindering your progress.
To review your games you need a stronger player. This can be a strong human or an AI. The advantages of AI like KataGo are that they are available anywhere and everywhere, they are patient and let you try any moves against them, and they don’t mind if you take a break and come back later.
The disadvantage of AI is that they cannot explain why they want to play a certain sequence. The AI is like a Zen master who lays out sequences for you and only says “good”, “bad”, “very bad” or “disastrous”. But if you don’t understand a move, you can keep asking until you can rationalise the AI’s decisions.
Here is my workflow:
I review every game I play; I just briefly go over the game without AI (most likely far too briefly), then upload the game to AI Sensei, where I look at all my mistakes that lose 3 points or more. A 3-point-limit already provides plenty of study material. If I don’t understand an AI sequence, I try out variations with the local KataGo.
Often in variations given by AI Sensei (or some other automatic review), KataGo will want me to play a certain move, then the opponent plays tenuki, then I get a second move in that area. My usual question then is “that’s nice, but what if the opponent does not tenuki?”. This is where the local KataGo can help.