In 2022, I put four sticky notes along the bottom of my monitor.

They were a physical blunder-check system. Before every move, I was supposed to inspect four things:

  1. My king.
  2. My opponent’s king.
  3. My pieces.
  4. My opponent’s pieces.

The idea was simple. Stop trying to play impressive chess long enough to notice checks, threats, loose pieces, and free material.

Then, in the very first game with the notes attached to the screen, I hung a rook.

The move that passed the checklist

The game was Mat20821–phzzl, a 15+10 rapid game on Chess.com. I had Black.

After an uneven opening, the position became tactical. I won material, activated my queen, and reached move 27 with less than three minutes against more than twelve for my opponent. I played:

27…Re8??

I saw that the rook attacked the queen. I did not see that the queen could simply take it.

28.Qxe8+

The sticky notes had not failed. I had followed an incomplete system. I checked the pieces as they existed before my move, but I did not perform one final inspection of the position my move would create.

So I added a fifth sticky note:

If I move a piece, is it defended?

That was the missing question.

A blunder is a new position

The useful moment comes after the candidate move appears.

Do not release the piece immediately. Place it on the destination square in your mind and look at the board again. What attacks it there? Which line did it uncover? Which piece stopped being defended when it moved? What checks, captures, and threats become available to the opponent?

A move is not safe because the piece was safe before it moved.

That sounds painfully obvious. It was not obvious with the clock running and a queen to chase.

Then my opponent hung a queen

After losing the rook, I kept playing. Two moves later, my opponent played 29.Bd6??, concentrating on an attack against my king and leaving the queen on e8 undefended.

I found 29…Rxe8.

The game flipped again. I had hung a rook. My opponent hung a queen. I eventually won by resignation.

That does not make my rook move good. A favorable result cannot travel backward through the score sheet and repair a blunder. It does make the game a perfect beginner lesson: the position after your mistake is still a position, and your opponent is still capable of making a mistake too.

The five-step check

Here is the system as it survived contact with an actual game:

  1. My king: Am I in check? What checks does my opponent have?
  2. Their king: Do I have a forcing check or mating idea?
  3. My pieces: What is attacked, loose, pinned, or overloaded?
  4. Their pieces: What can I capture or threaten?
  5. My intended move: On its destination square, is the piece safe—and what changed when it left its old square?

This will not eliminate every blunder. The point is to turn a vague intention—be more careful—into a repeatable action.

The fifth sticky note exists because the first four were not enough. That is how a useful system is built: make it, test it, let reality embarrass it, and revise it.

Then keep playing.

The practical method now lives in the evergreen guide: The Five-Step Blunder Check.