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.