[PC Gaming] Palamedes

[NickTheGreek]

File Name :: Palamedes
Author :: NickTheGreek
Category :: PC Gaming
Screenshot ::
Description ::
Play backgammon variants against award-winning expert AI.


Backgammon Variants
The only backgammon program that supports expert AI play in various backgammon variants including Tavli (Portes, Plakoto, Fevga), Narde, Nackgammon, Hypergammon, Takhteh. More variants added frequently!

Palamedes has won at the backgammon computer Olympiad two times in 2011 and in 2015. You can also view photos of the 2011 event. and photos of the 2015 event.




View File

[NickTheGreek]

Manual





Author: Nikolaos Papahristou
Manual Version: 0.06 2013/08/08





Introduction


Palamedes is a project dedicated to offering expert playing computer
opponents at backgammon and several other variants. Currently users of
Palamedes can play the variants Portes, Plakoto, Fevga collectively
called Tavli (Greek backgammon) and the variants Nackgammon,
Hypergammon, Narde, Takhteh. For position evaluation, Palamedes uses
neural networks trained by a form of temporal difference learning and
millions of self-play games. Palamedes also offers simple ways of
storing and loading games, as well as simple analyzing tools.


License/Warranty


Palamedes is free software. This means that the user can use all of
the features of the software at no cost. If you have paid to obtain this
software, get your money back. Selling this software is absolutely
prohibited. Distributing this software in any form is permitted only if
it is approved by the author. Palamedes can be downloaded from the [url=http://ai.uom.gr/nikpapa/Palamedes]official program website.


THE SOFTWARE IS PROVIDED “AS IS”, WITHOUT WARRANTY OF ANY KIND,
EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.


Installation


System Requirements


Palamedes should be able to run under all Windows versions. However, versions before Windows XP have not been tested.
As of version 0.46a, Palamedes requires a x86 processor that supports SSE2. Processors bought after 2006 should be fine.


Latest version (after 0.43a):


Download and run the Palamedes_install.exe from the program website.
Follow the installation instructions. Run the Palamedes shortcut on the
desktop for the program to start.


Previous versions (before 0.43a):


Download the respective version’s .zip file from the program website.
Decompress on a directory of your choice. Run the .exe from the
directory for the program to start.


Game Rules


Palamedes supports the backgammon games Portes, Plakoto and Fevga.
All the games are two player games that can be played at a 24-point
board, comprised of 4 6-point quadrants. The last quadrant of each
player is called home board for that player. The players have
15 men or checkers at their disposal that can be moved according to the
rolls of two dice and the rules. The following section specifies the
rules of each game.


Portes (Backgammon)


Setup: Each player has 2 checkers on the opponent’s
one-point, 5 checkers on the opponent’s twelve-point, 3 checkers on his
own eight-point and 5 checkers on his six-point.





To start: Each player rolls one die and the higher number goes first. That player then rolls the dice again to begin his first turn.


Movement: The roll of the dice indicates how many points or pips the player is to move his checkers. The following rules apply:

• A checker may be moved only to an open point, one that is not occupied by two or more opposing checkers.
• The numbers on the two dice constitute separate moves. For example,
  if a player rolls 5 and 3, he may move one checker five spaces to an
  open point and another checker three spaces to an open point, or he may
  move the one checker a total of eight spaces to an open point, but only
  if the intermediate point (either three or five spaces from the starting
  point) is also open.
• Doubles are played twice. For example, a roll of 6-6 means the player has four sixes to use.
• You must use both numbers of a roll if possible, or all four numbers
  in the case of doubles. When only one number can be played, the player
  must play that number. Or if either number can be played but not both,
  the player must play the larger one. When neither number can be used,
  the player loses his turn. In the case of doubles, when all four numbers
  cannot be played, the player must play as many numbers as he can.

Hitting: A checker sitting alone on a point is called a blot. If an opposing checker lands on a blot, the blot is hit and placed on the bar.


Entering from the bar: Any time you have one or more
checkers on the bar, your first obligation is to enter those checker(s)
into the opposing home board. You enter a checker by moving it to an
open point corresponding to one of the numbers on the rolled dice. If
you are able to enter some but not all of your checkers, you must enter
as many as you can then give up the remainder of your turn.


Bearing Off: Once you have moved all fifteen of your
checkers into your home board, you may begin bearing off. You bear off
rolling a number that corresponds to the point on which the checker
resides, and then removing that checker from the board. If there is no
checker on the point indicated by the roll, then you must make a legal
move using a checker on a higher-numbered point. If there are no
checkers on higher-numbered points, you must remove a checker from the
highest point that has a checker.


Scoring: The first player to bear off all fifteen
checkers wins the game. If the losing player has borne off at least one
checker, he loses only one point; otherwise he loses two points.


There is no doubling in this game.


Plakoto


Setup: Each player starts with fifteen checkers on
the opponent’s one-point. The checkers move around the board in opposite
directions as shown in the diagram below.





Object: The object of the game is to bring all your
checkers around to your own home board and then bear them off. The first
player to bear off all of his checkers wins the game.


To start: Each player rolls one die and the higher
number goes first. That player then rolls the dice again to begin his
first turn. After the first game, the winner of the previous game goes
first.


Movement: The roll of the dice indicates how many points or pips the player is to move his checkers. The following rules apply:

• A checker may be moved only to an open point, one that is not
  occupied by two or more opposing checkers. Also a checker cannot be
  moved to a point pinned by the opponent.
• The numbers on the two dice constitute separate moves. For example,
  if a player rolls 5 and 3, he may move one checker five spaces to an
  open point and another checker three spaces to an open point, or he may
  move the one checker a total of eight spaces to an open point, but only
  if the intermediate point (either three or five spaces from the starting
  point) is also open.
• Doubles are played twice. For example, a roll of 6-6 means the player has four sixes to use.
• You must use both numbers of a roll if possible, or all four numbers in the case of doubles.

Pinning the opponent: There is no hitting in this
game. Instead, if you land on a point occupied by a single opposing
checker, the opponent’s checker is trapped until you remove your
checker. Two of your checkers on a point or one of your checkers pinning
the opponent’s checker creates a block which the opponent cannot land
or touch down on.


Pinning the mother checker: The last checker on your starting point is called the mother.
If this checker gets pinned by the opponent before it has left the
start, the game is over and you lose two points. The only exception is
if the opponent still has checkers on his starting point, since in this
case his own mother is still threatened. A game in which both mothers
are pinned is a tie.


Bearing Off: Once you have moved all fifteen of your
checkers into your home board, you may begin bearing off. You cannot
bear off when you have one or more checkers pinned inside your home
board. You bear off rolling a number that corresponds to the point on
which the checker resides, and then removing that checker from the
board. If there is no checker on the point indicated by the roll, then
you must make a legal move using a checker on a higher-numbered point.
If there are no checkers on higher-numbered points, you must remove a
checker from the highest point that has a checker.


Scoring: The first player to bear off all fifteen
checkers wins the game. If the losing player has borne off at least one
checker, he loses only one point; otherwise he loses two points.


Fevga


Setup: Each player starts with fifteen checkers on
the rightmost point of the far side of the board, at diagonally opposite
corners from each other. They both move in the same direction,
counterclockwise, around the board.





Object: The object of the game is to move all your
checkers around the board and bear them off. Red bears off at the
lower-right; Green bears off at the upper-left.


To start: Both players roll one die and the higher
number goes first. That player rolls the dice again to begin his turn.
After the first game, the winner of the previous game goes first.


Movement: The roll of the dice indicates how many points or pips the player is to move his checkers. The following rules apply:

• A checker may be moved only to an open point, one that is not occupied by any opposing checkers.
• The numbers on the two dice constitute separate moves. For example,
  if you roll 5 and 3, you may move one checker five spaces to an open
  point and another checker three spaces to an open point, or you may move
  the one checker a total of eight spaces to an open point, but only if
  the intermediate point (either three or five spaces from the starting
  point) is also open.
• Doubles are played twice. For example, a roll of 6-6 means you have four sixes to use.
• You must use both numbers of a roll if possible, or all four numbers
  in the case of doubles. If you can play one number but not both, you
  must play the higher one.

First checker away: Your first checker must pass the
opponent’s starting point, before you may move any of your other
checkers. For example, after White’s initial roll of 6-6, he moves his
first checker forward six spaces, but then he is stuck. He cannot move
the same checker any further because it is blocked, and he cannot move
any other checker, until the first checker is past the opponent’s
starting point.


No hitting: A major difference between Fevga and
other forms of backgammon is that there is no hitting in this game. One
checker by itself controls a point, and an opposing checker may not land
or touch down there.


Limitation on primes: You are not allowed to block
all six points in your starting table and in the starting table of the
opponent. If you have built a prime (six consecutive blocked points),
and your opponent has collected all his checkers onto the one point
behind your prime, then you must unblock a point in your prime to allow
him a chance to move.


Bearing off: Once you have moved all fifteen of your
checkers into their finishing table, you may begin bearing off. You
bear off a checker by rolling a number that corresponds to the point on
which it resides, then removing the checker from the board. If there is
no checker on the point indicated by the roll, you must make a legal
move using a checker on a higher-numbered point. If there are no
checkers on higher-numbered points, you must remove a checker from the
highest point that has a checker.


Scoring: The first player to bear off all his
checkers wins the game and scores one point. If the winner bears off all
his checkers before the loser has borne off any, he gets two points.


Narde


Narde is a Russian game similar to Fevga (popular in Greece) and Moultezim (popular in Turkey).


Setup: Each player starts with fifteen checkers on
the rightmost point of the far side of the board, at diagonally opposite
corners from each other. They both move in the same direction,
counterclockwise, around the board. The starting setup is identical to
Fevga.





Object: The object of the game is to move all your
checkers around the board and bear them off. Red bears off at the
lower-right; Green bears off at the upper-left.


To start: Both players roll one die and the higher
number goes first. That player rolls the dice again to begin his turn.
After the first game, the winner of the previous game goes first.


Movement: The roll of the dice indicates how many points, or pips, the player is to move his checkers. The following rules apply:

• A checker may be moved only to an open point, one that is not occupied by any opposing checkers.
• The numbers on the two dice constitute separate moves. For example,
  if you roll 5 and 3, you may move one checker five spaces to an open
  point and another checker three spaces to an open point, or you may move
  the one checker a total of eight spaces to an open point, but only if
  the intermediate point (either three or five spaces from the starting
  point) is also open.
• Doubles are played twice. For example, a roll of 6-6 means you have four sixes to use.
• You must use both numbers of a roll if possible, or all four numbers
  in the case of doubles. If you can play one number but not both, you
  must play the higher one.

Moving off the “head”: The starting point for either
player is called that player’s “head.” You may move only one checker
off of your head each turn. The one exception is the first roll of the
game in which you may move two checkers off your head. Two off the head
is forced when a player rolls 3-3, 4-4, or 6-6 for his first roll.


No hitting: A major difference between Narde and
other forms of backgammon is that there is no hitting in this game. One
checker by itself controls a point, and an opposing checker may not land
or touch down there.


Limitation on primes: You may not build a prime (six
consecutive blocks) in front of all of the opponent’s checkers; at
least one opposing checker must be in front of your prime.


Bearing off: Once you have moved all fifteen of your
checkers into their finishing table, you may begin bearing off. You
bear off a checker by rolling a number that corresponds to the point on
which it resides, then removing the checker from the board.


If there is no checker on the point indicated by the roll, you must
make a legal move using a checker on a higher-numbered point. If there
are no checkers on higher-numbered points, you must remove a checker
from the highest point that has a checker.


Scoring: The first player to bear off all his
checkers wins the game and scores one point. If the winner bears off all
his checkers before the loser has borne off any, he gets two points.


Hypergammon


Setup: Each side starts with just three checkers:
one on each of the opponent’s one-point, two-point, and three-point.
Palamedes also offers more complex variations up to 6 checkers per
player. In Palamedes, standard Hypergammon is called Hypergammon-3. When
4 checkers are used per player then the game is named Hypergammon-4,
for 5 checkers we have Hypergammon-5 etc.


Play: The rules are the same as for standard
backgammon/Portes. You make points, hit opposing blots, and bear your
checkers off just as in the regular game.


Scoring: The scoring is the same as in regular backgammon: the winner gets one point for a normal win, two points for a gammon.


Takhteh


Takhteh (also spelled “Takhte”) is the Persian name for backgammon.
The rules are similar to Portes but not exactly the same. The
differences are:

• There is no “hit-and-run” in the player’s home board.
• You may not unnecessarily waste pips during bearoff.

Game Screen





Program Menu: File: Items related to files -mostly
game files, Game: Items related to playing a game, Help: Show this help
page and the about dialog.


ToolBar Icons: Here the most common user actions are grouped as icons.

• New: Starts a new game
• Open: Opens an existing game file
• Save: Saves the current game to file
• Demo: Starts a demo session where Palamedes plays
  against itself using the best strategy available. The Demo can be
  stopped by pressing Esc.
• Undo: Undos the current move of the player. This
  means that when the player is on the move, it places the checkers in the
  position after the player rolled the dice.
• Resign: Press this button when you want to resign the current game.
• Options: Opens the program options.
• Stats: Opens the statistics page.
• Exit: Close the program and exit.

Pipcount Display: This area, on the right of the
toolbar icons, displays the Pipcount for each player in the current
game. Pipcount is total number of points (pips) that a player must move
his checkers to the home board and bear them off.


Board: The backgammon board where the games can be played. It consists of:

• 4 quadrants of 6 points, each labeled from 1 to 24.
• the bar point which is in the middle of the board.
• the bearoff points of both players in the right side.
• Palamedes dice area: this area displays the dice rolled by Palamedes.
• Player dice are: this area displays the dice rolled by the user.

Scoresheet: This is a non-editable grid where the
dice rolls and the moves of both players are displayed automatically
after the completion of a move. There is a header column that displays
the move number of each player. Next to this header, the grid has 4
columns:

• Column 1: Dice rolled by Palamedes
• Column 2: Move played by Palamedes
• Column 3: Dice rolled by the user
• Column 4: Move played by the user

When the game is over (or when not playing in auto_checker mode), the
user can click on any cell of the grid and the board will instantly
show the respective position. Navigation through the grid cells can be
made using the standard keyboard buttons:

• Tab: Go to the next cell to the right. If it the last column, go to the cell at the next row-first column.
• Shift+Tab: Go to the previous cell to the left. If it is the first column, go to the cell at the previous row-last column.
• Arrow keys: Go to the respective direction within the confines of the grid.
• Page Up: Go to the first row visible in the grid.
• Page Down: Go to the last row visible in the grid.
• Home: Go to the first column of the current row.
• End: Go to the last column of the current row.

StatusBar: This area displays program messages.


How to play a game


The user can start the game by pressing the toolbar button “New” or
by selecting File->New from the menu. The following dialog will
appear:





Select game type: Here the user selects the type of game he wants to play (Portes, Plakoto, Fevga, Narde, HyperGammon, Takhteh)


Select AI opponent: Here the users selects the
strategy (neural network) that will be used by the Artificial
Intelligence (AI) computer opponent. The strategies are sorted in
ascending performance. For example Portes (pubeval) is weaker than
Portes 160, which in turn is weaker than Portes ACG-13.


Portes (pubeval) is a benchmark neural network created by Gerald
Tesuaro. Portes ACG-13 is the neural network that Palamedes used at the
2011 Backgammon Computer Olympiad where it took the gold medal.


Select lookahead: Here the user selects how far the
computer should search the game tree. 1-move means that the computer
will search only the available moves in the current position/roll.
2-move means that the computer will search all 1-move positions of the
current position/roll and then analyze all the available moves for the
opponent for every dice roll possible. 2-move is almost always better
than 1-move but is slower. If the Threshold option is different than
zero, then the 2-move look-ahead only considers the best k 1-move
positions before going to the next level (where k= the threshold value).


Enter your name: The user can put his name here.
This will be displayed in the scoresheet. The program automatically
displays the name used in the last game played.


The game starts with each side rolling a die to determine which plays
first. If it is the computer’s side to move, the dice are rolled and
displayed at the computer dice area and the move is played
automatically. If it is the player’s side to move, the dice are rolled
at the player’s dice area and the user must move the checker according
to the rules. In order to move a checker, the user must first click the
point where the checker resides and then click the point where he wants
to move it. If the user wants to take back his current move, he can
press the Undo button and the board will go back to the position after
the dice roll was made. The program checks if the move played was valid
according to the game rules. If the move was illegal, the board returns
to the position before the move was made (undo) and the user must renter
the move.


The user can resign the game at any moment by pressing the “Resign”
toolbar button. If the user has borne off at least one checker, then the
game is declared a single loss otherwise the game is declared a double
loss.


Game analysis


Palamedes offers a move by move analysis feature. This feature is
enabled by clicking the ”Analyze” button, when the user selects a dice
roll (1st and 3rd columns on the scoresheet). Note that in order for
analysis to work, the game must be ended. The following dialog appears:





The selected position to be analyzed is shown at the
upper left corner. The user enters the depth of the search (search
plies), the threshold number k (for 2-move look-ahead) and the neural
network engine that will perform the analysis. After the analysis button
is pressed, the grid on the right side is filled with all the available
moves scored by the neural network selected. The available moves are
sorted in descending order, the best move goes first.

• Move: a move to be analyzed (eg. 24/18 18/15)
• Val(1ply): The score of the neural network. This value is computed from the W(1-ply), WD(1-ply), LD(1-ply).
• W(1ply): The estimated probability if winning the game at 1-move search, regardless if it is single or double game
• WD(1ply): The estimated probability if winning a double game at 1-move search.
• LD(1ply): The estimated probability if losing a double game at 1-move search.
• Val(2ply): The score of the neural network. This value is computed from the W(2-ply), WD(2-ply), LD(2-ply).
• W(2ply): The estimated probability if winning the game at 2-move search, regardless if it is single or double game
• WD(2ply): The estimated probability if winning a double game at 2-move search.
• LD(2ply): The estimated probability if losing a double game at 2-move search.

Val(2ply), W(2-ply), WD(2ply) and LD(2ply) are filled only when Search Plies=2 is selected in the left side options.


Program Options


Program options are divided into four parts: general, board, rules, and dice.


General

• Check for updates at startup: Every time the
  program starts, the program will check whether a new version is
  available. The computer must be connected to the internet for this check
  to work. The availability of a new version can be also checked by
  pressing the “check now” button. (Default: checked)
• Auto save games: If this option is checked, the
  game will be automatically saved in the program directory when the game
  ends. The format of the game filename is YYYYMMDD_hhmmss.tavli.
  (Default: checked)
• Player moves must always be legal: This option is currently disabled.
• AI can resign: When checked the AI will offer its resignation when the odds of lousing a double game are very high. (Default: checked)

AI pruning

• LookAhead Pruning: Enter in this box how many moves
  the program should keep before expanding to the second ply. If 0, then
  all moves are considered. This option is only relevant when 2-move
  look-ahead is selected at the start of a game. (Default: 0)
• Prune when value difference greater than: If the
  difference of the value of a move in 1-ply and the value of the best
  move is greater than the number in this box then this move will not be
  expanded in 2-ply. For example, if this value is set at 0.5 and a move
  has a value at 1-ply at 0.1 while the best move has value 0.7, this move
  will not be expanded at 2-ply (pruned) because the difference with the
  best move is 0.6, which is greater than the set value of 0.5. If this
  value is set at 0 then no pruning of this type is taking place. This
  option is only relevant when 2-move look-ahead is selected at the start
  of a game.
• Language: Select the language of the program.
  Currently only English, Greek and German are supported. Language change
  needs a program restart to be applied (Default: English).

Board





Gameplay

• Automatically roll player dice:
  When checked, the dice of the player will be rolled automatically
  shortly after the computer completes a move. When unchecked, the player
  will need to press inside the dice area for the player dice to roll.
  (Default: checked)
• Automatically roll computer dice: When checked, the
  dice of the computer will be rolled immediately after the player
  completes his move. When unchecked, the player will need to press inside
  the dice area for the computer dice to roll. (Default: checked)
• Automatically play forced moves: When checked and the player has only one legal move, this move will be played automatically. (Default: checked)
• Player can move only highlighted points: When
  checked each time the player moves the points that can be legally moved
  will be highlighted with lime coloring and the player can only move
  from/to these points. (Default: checked)
• Animation speed: The time it takes (in
  milliseconds) for a single checker to move from its starting point to
  the resulting point. (Default: 1000 ms)

Board Appearenece

• Player’s checker color: Select the color of your checkers. (Default: red)
• Opponent’s checker color: Select the color of the computer’s checkers. (Default: lightgreen)
• Odd points color: Select the color of the odd board points. (Default: saddlebrown)
• Even points color: Select the color of the even board point. (Default: palegoldenrod)
• Board background color: Select the color of the boards’ background. (Default: ivory)

Rules





The following rules of Portes, Fevga and Plakoto can be enabled or
disabled. Changing these options in the middle of the game has no effect
on the current game. The rule changes are always applied at the next
new game. These rules do not apply on other similar variants (e.g
changing Fevga rules do not change the rules when playing Narde).


Portes Rules

• Egyptian Rule: When checked the player cannot stack more than five checkers on a single point. (Default: unchecked)
• Nackgammon start position: Each player starts with
  two checkers on the opponent’s one-point, two on the opponent’s
  two-point, four on the opponent’s twelve point, three on the
  eight-point, and four on the six point. (Default: unchecked)
• No hit and run in home board: You may not run for
  cover after hitting an opposing blot in your own home board. If you
  choose to hit within your home board, you must cover the hitting checker
  with another of your own checkers or leave it exposed. (Default:
  unchecked)
• No pip wastage in bearoff: You may not
  unnecessarily “waste pips” during bearoff. This means you should always
  bear off a checker where possible rather than use a smaller number to
  move that checker forward. (Default: unchecked)

Fevga Rules

• Enforce Fevga starting checker rule: When checked
  the following rule is in place: “the first checker must pass the
  opponent’s starting point, before you may move any of your other
  checkers” (Default: checked)
• Do not allow prime in front of our starting point: When checked the player on the move cannot make a prime in his first 6 points. (Default: checked)
• Do not allow prime in front of opponent starting point: When checked the player on the move cannot make a prime in front of the opponent’s starting point. (Default: checked)
• Enable Fevga’s blocking rule: When checked players cannot make moves that completely block the opponent.

Plakoto Rules

• Continue game if mana point is pinned: When
  unchecked in Plakoto, the game will terminate immidietaly after a mana
  point is pinned as a double game for the pinning player. When checked
  the game will continue until the first pinning player releases his mana
  point. If both players pin the mana points, then the result is a draw.
  (Default: unchecked)
• Tapa start position: When selected, Plakoto games
  will start with each player having 5 checkers in their first 3 points,
  instead of 15 checkers in the first point.

Dice

• Manual Dice: If this is option is checked, each
  dice roll must be entered by the user. Unselected, the dice are rolled
  by the computer. (Default: unchecked)
• Dice Generation Method: This option selects the pseudo-random dice generator algorithm. Four algorithms are supported:
  • Linear Congruential
  • Mersenne Twister (Default)
  • Lagged Fibonacci
  • Ranlux
• Seed: This a number used to initialize the dice
  generation algorithm. At program startup the seed is updated from the
  system clock. Whenever the seed is changed by the user, the selected
  dice generation method will always generate the same dice sequence for
  the updated seed number.
• First roll not double: When this option is checked, the first roll of the the player starting the game cannot be a doubles roll. (Default: unchecked)

Advanced Features


Open/saving .tavli files


The current game played at the board can be saved by pressing the
“Save” toolbar button or from File->Save menu item. The game is
stored in a text file with a .tavli extension. This file can be read by
any text editor like notepad. Stored games can be loaded using the
“Open” toolbar button or the File->Open menu item.


File->Load NN


Loads a new Neural Network from a file. This function is used by the developers to test new neural networks.


Game->Delete remaining moves


After a computer move the user can click any position at the
scoresheet and then select this item to delete all the moves that follow
from there on. Since the rest of the game is deleted, play continues
from the current position.


Plakoto Pin Databases


Starting from version 0.44a, Palamedes includes 6-point, 1-sided
databases for Plakoto’s pinned positions inside the home board. There
are 5 files named Plakoto_xb.pinDB, where x=1 to 5 stored in the program
directory that are loaded at program startup. The databases are used
when in a Plakoto game the AI has pinned one checker in his home board
and the player has also pinned one computer checker. The values stored
in the databases are the weighted-average number of plies to unpin,
which is the expected number of plies the moving player will unpin the
pinning point with perfect play. When these databases are used, the
program selects the move that results in the position with the largest
value.


The databases can also be used in the analysis window. If the
position analyzed has the above characteristics, there will be another
option available named “Plakoto_DB”. This will show the value stored in
the databases sorted in descenting order.


Feedback


Comments and suggestions can be mailed to nikpapa@gmail.com.


Bugs and feature requests can be placed at the [url=https://github.com/nikpapa/Palamedes/issues?sort=created&state=open]Palamedes Issues github page.

Source : Palamedes Official Page Manual