Types of Blunders

I was thinking about this as I was running through the design for a database on tracking games. What are the most general categories for blunders/errors in chess?

Here are some I thought up. I would like some more contributions.

• Missed Tactic: Defensive
• Missed Tactic: Offensive
• Hanging Piece
• Hanging Pawn
• Incorrect Calculation (this is probably to vague)
• Time Trouble

The idea is that games in which you make an error you would tag with the blunder type and then be able to run reports to get information about the most frequent errors you make.

I did something like this with my games.

Here are some of the errors I rated as most frequent:

Knight forks

Pins ( E.g. allowing a piece/square guarded by a pinned piece to be taken/used)

Overlooking checks by either you or the other player

Horizontal rook attacks

Removing your own guard of a piece

Counting errors in calculation (e.g. thinking you will end up a piece up but only being up the exchange/ my own counting errors seem to have cropped up mostly when rooks and minor pieces together are being traded off the board)

Missing strong refutations to a tactical attempt

There were others but those were for me the most frequent. 

You may also run into the same problem I had, some blunders are hard to categorize. 

Lately I have been switching the knights and bishops when setting up an OTB game. I honestly don't know why.

Hope that helps!!

 That's why I am trying to be as generic as possible. Some of the ones you listed, for exmple, would all be classed as either missed tactic (either offensive or defensive). The problem I am really having is making other categories general enough to be a useful "class" without being so general that they become meaningless.

how can you use code to write this?

Im not sure hanging PAWN is a blunder

It really depends on how granular you want you want your database to be. If you want to track all the details, and assuming you don't want to track blunders but also other weaknesses, you could go as far as the following:

• Overlooked opponent tactics:
  • Mate in one,
  • Mate in two,
  • Knight fork,
  • Pawn fork,
  • Other double attack involving a check,
  • Other double attack without a check,
  • Pin,
  • Deflection,
  • Discovered attack without check,
  • Discovered attack with check,
  • Skewer,
  • Trapped piece,
  • Decoy,
  • Intermediate move,
  • Back-rank problem,
  • Perpetual check (i.e. opponent saved losing game by perpetual),
  • Stalemate.
• Overlooked tactical opportunities (i.e. in your own moves)
  • Basically the same list as above.

Of course, you could combine some of the above categories into a single one, e.g. the forks, etc. I'm curious whether anyone has tried this. I recently asked for tips for building a blunder database, but got no responses from people doing this. I suppose most people don't want to bother with it.