**Personal Projects** Gary Linscott - glinscott@gmail.com LCZero (2017) ============= Modern chess AI, through extensive and systematic testing on top of the alpha-beta framework has become incredibly strong (see the Fishtest section). [AlphaZero](https://arxiv.org/abs/1712.01815) turned it all on it's head, showing that deep nets, learning purely from self-play could challenge the best of the old world, and using a completely different type of search as well (MCTS). [LCZero](http://lczero.org) started life as a fork of [LeelaZero](https://github.com/gcp/leela-zero), hence the name, Leela Chess Zero. There is a fantastic community that has taken the project on, and is running it now at https://github.com/LeelaChessZero/lczero. The major problem with the AlphaZero approach is it requires a truly huge amount of compute to train the engine. This required a distributed, volunteer based project - similar to Fishtest. As of this writing in Oct. 2018, it's getting close to the strength of top engines, which is pretty amazing. 176 users in the last day have played 973932 training games! ![LCZero training progress](lczero.png) Porting the engine to Chess was interesting, mostly around getting the custom OpenCL kernels working well. The server and client are written in Go, and communicate via HTTP, which I felt worked very well, especially the ability to cross-compile to any OS very easily. The server is backed with Postgres, which also has worked well -- except when I was storing the PGN data in the game results table. That turned out to be a disaster, overwhelming Postgres, and requiring some major database surgery. The training pipeline is all in python and Tensorflow. Fishtest (2013) =============== [Fishtest](https://github.com/glinscott/fishtest) (http://tests.stockfishchess.org/tests) is a distributed testing environment for [Stockfish](https://github.com/official-stockfish/stockfish) - the strongest[^1] chess engine in the world. Fishtest has enabled Stockfish to become the strongest, and remain the strongest. It proved that scientific testing leads to continuous improvement. I started Fishtest because I hated babysitting my tests when trying out engine improvements. A common theme was having five ideas, but only the machine resources to test one. Fishtest hands out the tasks to a network of volunteer machines. It uses the [SPRT](https://en.wikipedia.org/wiki/Sequential_probability_ratio_test) algorithm to make a statistically optimal choice about how many games to play before making a pass or fail decision. Fishtest ended up being way more successful than I thought it would be. There is a vibrant community, with hundreds of different authors contributing patches to be tested, thousands of volunteers donating CPU time, and dedicated maintainers improving Fishtest itself. Fishtest introduced wide-scale distributed testing to Chess engine development, and made being open-source a huge advantage. When your program is open-source, you can easily distribute all your testing ideas out amongst volunteers. The commercial engines had to limit the distribution of the tests, usually to their local cluster. As a result, Stockfish has become the best overall engine by a significant margin, and shows no signs of slowing down. The image below, from [NCM](https://nextchessmove.com/dev-builds)[^2] shows progress in ELO, which is a logarthmic scale! ![SF ELO Chart](sf_rating.png) The core architecture is a server running python, backed by MongoDb. MongoDb has actually been very solid for Fishtest, not being the source of any major issues. The client is in python, and has some nifty tricks for self-updating. [^1]: [CCRL](http://www.computerchess.org.uk/ccrl/404/), [IPON](http://www.inwoba.de/), [FastGM](http://www.fastgm.de/) [^2]: https://www.sp-cc.de/ does a fantastic job testing SF as well. GarboChess.js (2011) ==================== https://github.com/glinscott/Garbochess-JS GarboChess.js was the first strong Javascript chess engine. It's a basic mailbox representation, with a very minimal evaluation. I optimized it for speed on the Javascript engines of the day, and it was able to search a high enough nodes per second to be stronger than most humans. ThinkGo (2010) ============== https://github.com/glinscott/thinkgo ThinkGo was a Windows Phone application to play Go. It uses MCTS with rollouts for the AI, but the phones were not powerful enough to really pose a challenge. ![ThinkGo](thinkgo1.jpg width="200px") ![ThinkGo](thinkgo2.png width="200px") ![ThinkGo](thinkgo3.jpg width="200px") GarboChess (2008) ============= https://github.com/glinscott/Garbochess-3 GarboChess was my first real chess AI. Eventually I got to the point where improving it required systematic testing. That's when I stopped and wrote Fishtest and switched to working on Stockfish :). SnezziDS (2006) =============== A SNES emulator running on the Nintendo DS at full speed, with sound (but relatively poor compatibility). I ported the SNES core from SnezziBoy, which was a GBA SNES emulator, and made some improvements to use the more powerful DS hardware, including my PocketSPC core for playing music. The source may be lost though, since bountysource went down. ![SnezziDs playing Super Metroid](https://www.youtube.com/watch?v=V8L7CyUmfiY) GarboDev (2005) =============== A GBA emulator in C#. Excellent compatibility, ran full speed on an Athlon 3200, with sound, and has a nice built in debugger. ![Zelda](gbaemu1.jpg) ![MarioKart](gbaemu2.jpg) PocketSPC (2005) ================ An SPC (SNES APU - the chip that played music for the SNES) emulator for the Nintendo DS with excellent compatibility. Ended up being used by all the main SNES emulators for the DS, SnesDS, SnezziDS and SnemulDs. It could also play the music from the games without running the game itself, due to the way the SNES was architected. The Nintendo DS actually had two CPUs, an ARM9 and ARM7 core, PocketSPC was capable of just running on the ARM7 core, leaving the ARM9 for the main CPU. The SNES APU was a remarkable chip, haivng 8 voice 16 bit sample playback, with filtering when PCs were still dealing with a 1 bit speaker. If you are interested, I highly recommend reading through the extremely detailed [documentation](https://github.com/gilligan/snesdev/blob/master/docs/fullsnes.txt#L1453) by Nocash, a famous emulation developer. Asheron's Call Plugins (2003) ============================= [Asheron's Call](https://en.wikipedia.org/wiki/Asheron%27s_Call) was one of the original MMOs. It had an amazing third party plugin system called Decal, and I wrote two plugins, one a connector to Winamp, the other a tool to calculate which items would be mostly likely to drop if you died (a familiar issue for those that played Asheron's call was losing your best items, and then being unable to recover them because the enemies were too strong without your good equipment). ![](dip1.jpg)