Move generation

The first step is move generation.  I have committed myself to Java and bitboards for Vicki 2.0.  The advantage of Java is that it is much more platform independent than C... well, mostly.  Bitboards is also a good move, given that it is theoretically faster than the postbox method and besides, it is something interesting to learn.

So the list of tasks for the next few days is as follows:

1.	Set up data structures	Done
2.	Set and get board (FEN-based)	Done
3.	Simple textual display	Done
4.	Move generation for non-sliders (pawns, knights and kings)	In progress...
5.	Move generation for sliders (bishops, rooks and queens)	Pending
6.	Make move	Pending
7.	Unmake move	Pending
8.	Perft testing	Pending

For now, the representation simply contains positions for each of the pieces.  The derived pieces will be added later.

Something stirring in the shadows...

I have only fond memories of Vicki...  The website is still up, but Vicki has not used a clock cycle in years.  The current release is several years old... written in C.

I am currently (as in already busy) rewriting Vicki.  Vicki 2.0 is a complete rewrite of the engine, reusing nothing but the name.

I am not looking at any existing computer chess code and I am avoiding any heavy bias to single papers and single units of theory - trying my own. The research in computer chess is all but exhausted.  So all that is left is to redesign the wheel for the fun of it and looking at existing code will spoil it for me... Vicki is not meant to "extend" the envelope of computer chess.  It's my Everest and South Pole.  

Vicki 2.0 is being written in Java.  Java's speed is comparable to C and C++ (in some people's opinions!) Also, I want something which is easily transferable between Linux and Windows platforms.  C does not really cut it for me any more.

Board representation will the elusive bitboard (or bitmap) technique.  It cannot be that hard... (famous last words!) and I cannot ignore it's advantages any longer.

I hope to post regularly and have something on the main website up and running soon.

Ping...

I've not posted for over a year.  Although I have not had much time to work in Vicki, the engine is definitely not dead.

I will start with a rewrite in the foreseeable future.  I am not yet sure which direction I'd like to take with Vicki - but I am toying with the following:

1. Possibly rewriting the engine in Java.  The speed difference between Java and C is negligible, when the number of objects used are limited.  Java also has better testing frameworks (well, from what I could find) and is platform independent.  I can also throw in my own GUI, if I like.
2. General improvement on absolutely everything from move generation write through to opening/ending databases.
3. Multi-threaded searching for multi-core systems.  I have access to some serious hardware at work (i.e. 64Gb RAM with 8 quad core processors).  Would be interesting to use of of those for a tournament!
4. I would like to finally get learning right!
5. Full-time up server playing on servers.

Watch this space!

Delays

Seems like I'm going to need a few more days. I've manged to split the move generation so that I now incrementally generate moves and search them (as appose to generate all the moves at once). This seems to be paying off. However, I'm having some transposition table problems again!

I'm hoping for end January.

Resurrected? ...or just out of the coma?

I guess life happened while I was busy working on my chess engine. I few months ago, I dumped the entire engine and started fresh. Then after a month or so, I dumped that idea and went back to the original codebase. I started integrating the sections of code that I rewrote and improved. To be frank, large sections of code in current release of Vicki is a terrible mess and these needed to be rewritten. I'm almost done with that.

I have already rewritten the move generation, which resulted in a speed increase of around 10%. I’ve also changed the representation of the move (I use a 32 bit integer for this) so that a full 8 bits are available for move ordering (this use to be 6). This change will greatly enhance the move ordering capabilities of Vicki.

I am now working on the actual search function and the transposition table. Apart from fixing a nasty bug with the transposition table (it returns a mate score, but just chases the king around with trivial end game positions), I also need to rethink all the pruning and speed-up techniques individually. I threw all these together without giving any much thought. I paid the price.

I'm also planning pondering, opening book learning and better interface support.

The next release is scheduled for the 4th of January 2010.

Vicki is back... and smelling blood!

Frustration

Even though I haven't posted in a while - Vicki is not dead. I'm having huge issues with Vicki at the moment which is taking up a great deal of time. The biggest problem at the moment is the transposition tables that are not working as it should. Every time I implement it, the engine plays weaker...substantially weaker. This can only be as the result of a bug. I hope to have this sorted out in the next week or so...

The transposition table is a very important component and I want that working first, before spending any more time with move ordering and evaluation as these elements share some common ground

Refactoing & revisiting

There are few things as annoying as a dormant blog - and here I am doing the exact same thing. I've recently revisit Vicki and I am in the process of refactoring the engine. I have found some bugs with the repetition detection and I am spending some time to get the engine stable. Once this is complete, I'll start working in getting the engine up to scratch.

One element that has been missing from Vicki is decent testing. For the time being I've identified 28 engines, ranging from weak to rather strong. The idea is to put Vicki in a gantlet against them and work with the final score as an indication of strength (2 rounds, from the starting position). Later on I'll try the test suites again.

Let see how it goes...