A Glossary of Terms

EGT, end-game table
Any tablebase or bitbase

Backward Move / Retrograde Move / Unmove
Normal move played backwards. Note that for reversible moves this can not
be distingushed from a normal move.

Black
The side we are calculating the lost positions for.

Chunk
Part of a tablebase that is stored contiguously

Constellation
A way in which a sub-set of the pieces can be placed on the board

Cycle
The process through which we derive the lost(N+1) positions from lost(N) positions

Disk chunk
Part of tablebase that is stored contiguously on hard disk,
and can be read or written without the necessity to read/write
any other part of the tablebase

DTM, Distance To Mate
The minimum number of moves it takes to enforce checkmate against optimal defense

DTZ Distace To Zeroing
The minimum number of moves it takes to do a non-reversible move that is winning, against optimal defense

Dynamic Piece
A piece that occurs on all possible squares in a given slice

Forward Move / Normal Move
Move as you play it in a normal Chess game, including captures

Gather
Collecting different chunks of data from disk or memory to collect complete data 
for a slice in memory or cache, repectively

Leapfrog Cycle
A combination of the second half of one cycle, and the first half of the next

Lost position
A position that is won for white when black has the move.

Lost(N) Position
A lost position where it takes N moves to effect the win with best counterplay,
by whatever metric we measure the distance to winning.

Lost list
A run-length coded and compressed list indicating lost(N) positions for a single N and a single chunk

Pass
A traversal through the tablebase that touches every element of interest once

Potentially Lost Position
A position where black has the move, and can do at least one move that
gives white a forced win we are already aware of.

Predecessor / Parent Position
Position from which a given position can originate by a normal (forward) move

Predecessor Tablebase
A tablebase from which an end-game can be reached by an action in normal forward play
that changes the set of pieces present on the board (i.e. by a capture or promotion).

Retrograde Move / Backward Move / Unmove
Normal move played backwards. Note that for reversible moves this can not
be distingushed from a normal move.

Scatter
Writing a slice back to hard disk after splitting it up in chunks that reside
in far-apart locations on the disk, requiring a seek operation for each chunk

Slice
Part of a tablebase with a subset of the pieces kept on fixed squares. Often
prefixed by the name of the fixed piece(s), e.g. K-slice, P-slice.

Static piece
A piece that is on the same square in every position of a given slice.

Successor / Child Position
Position that originates from a given position by a normal (forward) move

Successor Tablebase
A tablebase to which an end-game can convert by an action in normal forward play
that changes the set of pieces present on the board (i.e. by a capture or promotion).

Uncapture
A capture played backwards. Note that in such a move the moving piece can
still only go to an empty square, but it leaves an enemy piece in the square
it came from.

Unmove / Backward Move / Retrograde Move
Normal move played backwards. Note that for reversible moves this can not
be distingushed from a normal move.

White
The side we are calculating the won positions for.

Winning distance
The value of the metric DTx for which we generate the EGT, e.g. DTM, DTZ.

Won bitmap
The data structure ued to indicate the won positions, one bit per position

Won Position
A position that is won for white when white has the move.