This page gives a short overview over the functionality of jCheckers. For feedback and installation, go to the main jCheckers page.

Opening and saving games

jCheckers uses the standard file format for checkers games, called PDN which stands for portable draughts notation. PDN is a text file format which can contain multiple games (some PDN databases come with my windows program CheckerBoard, and can be downloaded there). When you open a PDN database, jCheckers will display a list of the games that the file contains. Note: with large databases (such as the Open Checkers Archive with 20'000-something games), opening the database takes a long time. I hope I can improve this in future versions. To save a game, you should enter some information about the game, and then either create a new file with .pdn extension, or save to an existing .pdn file.

Copy and paste

The text field below the board traps the Ctrl+C and Ctrl+V keyboard shortcuts that are normally used for copy and paste, so I'm using plain C and V until I figure out how to fix this. When you copy a game, you get a PDN-style move output in the clipboard that you can paste into an email, and send it to a friend, who can select it and paste it into his jCheckers copy (or of course into CheckerBoard).

Levels of play

The jCheckers engine supports 4 levels of play:
  • Beginner level: on the beginner level, jCheckers will attempt to achieve a bad position and keep it at that. It also plays with only a 2-move lookahead, and is quite weak, so that even beginners should be able to beat it at this level.
  • Training level: on the training level, jCheckers will attempt to give you two-for-one shots. If it sees a move that allows you a shot (a tactical maneouver to win a piece), it will play this move and alert you that you now have a good move in the text area below the board. This feature doesn't work 100% properly, often it will tell you that you have a good move when in fact you have only one capture, but then you will have the good move after the capture. On this level, if you find the shots, you should win easily. But because jCheckers creates problems on-the-fly, you will probably improve your checkers tactics!
  • Fixed depth levels: You can set jCheckers to search 1 to 9 half-moves (so-called ply) ahead. On timed levels, it can search much deeper. The fixed-depth levels give you a good control over the playing strength of jCheckers. If you can beat the beginner level, try the 1-ply level next, if you beat that, then try the 3-ply level etc.
  • Timed levels: here, jCheckers will search for a specific amount of time. This is the most natural mode, but it can be frustrating because jCheckers has a very powerful checkers engine and you will have to be a very good player to stand a chance on these levels!

This page was last updated on March 29, 2010