Tips for building your own blunder database?

I've just read Alan-Safar Ramoutar's blog post A Self-Taught IM's 5-Step Guide To A Growth Mindset (June 2025). Much of the advice is relevant to life in general, since a growth mindset is beneficial in many areas of life, not just chess.

One of the pieces of advice in the blog post is to build a “Blunder Database”:

After each game, especially ones with major errors, add the position where you blundered along with a brief note explaining what went wrong. Over time, you’ll start seeing patterns, maybe you consistently miscalculate under time pressure, or maybe you overlook backward moves.

This database will reveal your patterns. Do you consistently blunder in time trouble? Add more timed puzzle sessions to your training. Do you overlook your opponent's defensive resources? Spend a week studying prophylaxis.

This is a great idea, but how many chess players actually do this? Since I started playing chess again at the end of March, I have been tracking major issues in my games in a spreadsheet, but this system is still a bit rough. (I have columns for specific tactics I overlooked, a column for notes about opening issues and one for notes about endgame issues.)

Have any of you tried this? Do you have any tips? Or do you just rely on external tools like ChessBlunders.org? 

I would guess that very few people take the time.

The Insights available to Chess.com diamond members tracks blunders, brilliant moves, mates, Missed mates, Forks, missed forks, moves made in book lines and so on.

Do you do something else to keep track of your mistakes? Do you have a different type of improvement plan?

That's a really good idea. If properly executed, it's very efficient way to improve. Though many people who does that get bored quickly and stop.

Just found this: The Spreadsheet I Used To Get To 2500 on NM Sam Copeland's blog.

As Baldrick would say, "I have a cunning plan"

try and make as many blunders as possible, this gives you a larger dataset to work from

Holaa

Not a blunder database, but a spreadsheet to track study time: Structured Practice by Chessmo.

I found a related thread from 2009: Types of Blunders, i.e. asking what types of blunders would be worth distinguishing in a blunder database.

Good idea, I've thought in something similar, writing in a notebook my biggest mistakes for example the dumb idea of attacking the queen without supporting your own attacker, ie losing a piece for free