https://play.google.com/store/apps/deta ... hessengine
I started developing the pulsar chess engine for computers in 1998. It was released for the first time in 2003. The final releases of pulsar were in 2009 and HG Mueller included that release in Winboard''s bundled computers. There has been an iOS version since 2014. Now on Android. It plays Chess, Crazyhouse, Atomic Chess. Loser's Chess, Giveaway and Three Checks.
The Android version of the Pulsar Chess Engine is a close copy of the iOS version using the same code base with modifications made for android. Both use the same C engine.
If you don't play variants try it for Chess. It has 8 difficulty levels before times games which are the hardest. I tend to just play Chess myself honestly but many friends play variants which drove me to teach it variants. But Chess has not been neglected. You will find it has a more mobile and tactical style than the typical engine. It would tend to lose against a similar strength engine in engine engine play as i skewed it's evaluate a bit to make it interesting to humans. The other engines see your miscalculations and close in.
If you go to settings, lower right, you will find a number of options including various wood options. I got all my wood from public domain images i found of wood grains.
Mike
Pulsar Chess Engine released on Android plays Chess, Crayhouse, Atomic and Loser's
Moderators: hgm, Rebel, chrisw
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adams161
- Posts: 626
- Joined: Sun May 13, 2007 9:55 pm
- Location: Bay Area, CA USA
- Full name: Mike Adams
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adams161
- Posts: 626
- Joined: Sun May 13, 2007 9:55 pm
- Location: Bay Area, CA USA
- Full name: Mike Adams
Re: Pulsar Chess Engine released on Android plays Chess, Crayhouse, Atomic and Loser's
I submitted an update of pulsar iOS with the new things from pulsar on android. New graphics, some delay in untimed games on pulsar's moves, half second, fix for Atomic En Passant capture bug and got the Pulsar Engines Draw code to avoid draw by reps working. It needed the correct data passed to the engine from the App.
Now the professional programs say always you cant avoid draws unless you hash every position. I never did this. I developed my own system of draw avoidance years ago that does not require hashing. I pass in the data of the board, 64 squares, and side to move for all previous moves. I check on root depth, depth one if current board with move on first ply repeats twice. If it does I make the score 0. Now alpha beta purists say that can't work. There is no second score tracked in an alpha beta search if if move it off the best move which i scored as 0. But somehow it always worked, I watched it hundreds of times. Maybe because i order the root moves it will grab the second best move in earlier searches. Maybe because its often in check when reps happen and i return negative scores for check mate solutions if it doesn't move out of check it knows to play another move to get it out of check. I've never had a problem with it.
Fixing this was a few dozen hours perhaps. I played maybe 50 games forcing it into draws by reps till i finally got confirmation on Android it was fixed. IOS also i thought i could just copy the code but because of mistakes and some differences ultimately took a dozen games today to confirm it was working. It really screws up an engine if it can easily be lead into reps. Any smart player can turn half their losses into draws. Now i wondered if maybe that was a selling point. But I want the Pulsar engine to know how to get a mate if it's ahead in the game. Not draw. So i'm happy it's fixed. Let me know if any issues.
Now the professional programs say always you cant avoid draws unless you hash every position. I never did this. I developed my own system of draw avoidance years ago that does not require hashing. I pass in the data of the board, 64 squares, and side to move for all previous moves. I check on root depth, depth one if current board with move on first ply repeats twice. If it does I make the score 0. Now alpha beta purists say that can't work. There is no second score tracked in an alpha beta search if if move it off the best move which i scored as 0. But somehow it always worked, I watched it hundreds of times. Maybe because i order the root moves it will grab the second best move in earlier searches. Maybe because its often in check when reps happen and i return negative scores for check mate solutions if it doesn't move out of check it knows to play another move to get it out of check. I've never had a problem with it.
Fixing this was a few dozen hours perhaps. I played maybe 50 games forcing it into draws by reps till i finally got confirmation on Android it was fixed. IOS also i thought i could just copy the code but because of mistakes and some differences ultimately took a dozen games today to confirm it was working. It really screws up an engine if it can easily be lead into reps. Any smart player can turn half their losses into draws. Now i wondered if maybe that was a selling point. But I want the Pulsar engine to know how to get a mate if it's ahead in the game. Not draw. So i'm happy it's fixed. Let me know if any issues.