One of the best uses I have found for game analysis is in providing new and interesting paths to investigate. Each game you play inevitably shows off your strengths and your areas for improvement. As an example, take Annotated Game #2 and what it showed/taught me.
- The early b3 opening variation in the English/QGD setup is viable if Black uses that move-order.
- I will need to study this type of opening setup more, focusing on plans and the middlegame transition.
- Strong players (GM Ulf Andersson, GM Bent Larsen) have played it. I can study their games in my database for more insights on the middlegame positions, plans, and types of endings reached.
- Don't be emotionally attached to particular moves (or not making particular moves) - this phenomenon prevented me from playing best on move 16 and directly lead to the loss.
- Be alert to a broader range of candidate moves for both yourself and your opponent and do not focus on a single move threat only. We both for example missed the strength of how ...b5 would cut off White's use of the c4 square for his pieces.
- Do what is necessary to "reset" your thinking after a difficult sequence, so as to not ignore new threats by the opponent.
Because the above points are all drawn from one of my own games, I will better remember both the specific moves/positions and the general lessons on psychology. The analysis and annotation process forced me to both understand the game better and also to be able to articulate that understanding. This is essentially the same as the teaching process - if you ever want to truly master a subject, put yourself in the position of teaching it or having to explain it to an outside audience.
It's worth noting that the type of game analysis that I'm doing, geared toward improving my chess playing, is not the same as some other types that are out there. There are purist annotators who are focused on determining the perfect move in each position. Others work more and longer concrete variations in and leave off explanations in words. These approaches have their merits, but I don't find either to be optimal for my own purposes.