7. Annex: Advanced Filter Usage

Warning

This section is for advanced users of blunderDB who wish to fully leverage the position search features.

Filters are at the heart of position analysis in blunderDB. Their use allows for searching specific positions with great precision. In this section, the use of filters through the COMMAND mode is detailed. The COMMAND mode can be accessed by pressing the SPACE key. It allows users to quickly combine filters and use the filter library with ease.

7.1. Command-line search for positions

To perform a search using filters,

  1. Switch to EDIT mode using the TAB key.

  2. Edit the current position.

  3. Switch to COMMAND mode using the SPACE key.

  4. Use the command s followed, optionally, by filters.

  5. Start the search with the ENTER key.

Warning

Don’t forget to clear the current position before starting a search (BACKSPACE key), if it isn’t the one you want, to avoid excessively filtering checker structures.

Note

The list of available filters in COMMAND mode is provided in Section 4.4.

7.2. Filter Library

The filter library allows the user to save search commands to facilitate their thematic studies.

To add a filter to the library,

  1. Switch to EDIT mode.

  2. Open the filter library by pressing CTRL-B.

  3. Edit the current position.

  4. Give a name to the filter.

  5. Edit the search command.

  6. Save the search command using the “Add” button.

Tip

While editing the command, you can use the UP and DOWN arrow keys to navigate through the command history.

To use a filter saved in the library,

  1. Switch to NORMAL mode.

  2. Open the filter library by pressing CTRL-B.

  3. Search for the desired filter.

  4. Double-click on the filter to start the search.

7.3. Examples

Here are some examples of using filters in COMMAND mode:

Type of position

Checker structure

Command

Races

s nc

Short races

s nc P<70

Hit to point 1

s m"6/1*"

Backgame 1-4

points 24, 21

s p>35

Take/Pass decision at 2-away 4-away

empty dice for top player, score 2a-4a

s s d

Too Good doubles

empty dice for bottom player

s d e>1000

Blitz with at least 20% gammon

point in jan, checkers on the bar

s g>20

Positions from Aachen2024 tournment

s t"Aachen2024"

One backchecker to bring back

s k1,1

Leave the 20-point anchor

point 20

s m"20/"

Prime vs prime

Set the primes

s

Ace-point bear-off

point 1 for the opponent

s P<60

Double with at least 20pip ahead

empty dice for bottom player

s d p<-20