Leela is a strong Go playing program combining advances in Go programming and
further original research into a small, easy to use graphical interface.
It is freely available, making it an ideal introduction to the game.
- Strong Go engine including support for multiple processors and GPU acceleration
- Strength >4 dan on 19 x 19, high dan level on 9 x 9
- 2008 Computer Olympiad Silver (9x9) and Bronze (19x19) medalist
- Featuring Deep Learning technology
- Easy to use graphical interface
- Adjustable board size (up to 25x25!), playing levels, handicap and komi
- Fixed strength and time based difficulty levels
- Chinese rules with positional superko
- SGF format loading and saving
- Rated game mode with auto-adjusting difficulty levels
- Analysis features including critical variations for each move and winning odds
Analyzing a game, showing the most probable moves.
What's this Deep Learning technology?
Leela contains an AI technique modeled after the human visual system and brain,
a deep stack of artificial neurons processing visual input with each layer combining the
previous ones into higher level features (a so called DCNN, deep convolutional neural network).
This "neural network" has been trained with more than 32 million
positions from professional-level go games and taught to predict which moves a pro
player would most likely consider. In 19x19 games the engine will query this deep
"neural network" during the search to focus on the most critical variations. The result
is a substantial raise in playing strength (about 6 stones), and a more human-like
playstyle, while still allowing the engine to innovate of its own.
What's the benefit of GPU Acceleration?
A GPU is typically much faster than a normal processor at doing the kind of
calculations the Deep Learning algorithms need. For example, an AMD R9 390 (mid-range
videocard) can find the worthwhile moves in a Go position about 30 times faster than an
Intel Core i5-6600 (mid-range CPU). Leela makes use of this to explore variations
deeper and in more detail. You can notice that in analysis mode the critical variations
displayed by the engine are much longer when GPU Acceleration is used.
What do I need to run the "GPU Accelerated" version?
You need a video card with OpenCL 1.1 (or later) capability. This is supported on all
recent AMD and NVIDIA cards. Make sure the latest drivers for the video card are
installed. The detected video card can be seen in the Help->l;About menu.
Can I run the "GPU Accelerated" version on the built-in graphics of my CPU?
This only makes sense if the built-in GPU is faster at doing the Deep Learning calculations
than the CPU itself. Intel CPUs are typically very fast, with a weak built-in GPU,
so this is not recommended. AMD APU's typically have a slow CPU but a fast GPU, so
it would be worthwhile on those.
Does it work on Linux?
The "engine only" download has Linux binaries included, which can be used with any Go GUI that supports the GTP protocol (almost all of them do). To use the OpenCL version you must have OpenCL drivers and an OpenCL ICD installed. The installer and graphical interface work and are fully functional under wine-1.6.2 or later.
Leela 0.7.0 (2016-09-30)
- Larger DCNN and hence better move pruning.
- Fuseki library built from professional games included. Speeds up opening play.
- (GPU version) Faster dispatching to GPU, speeding up tree search.
- Better selection of critical variations during the tree search.
- Altogether about half a stone stronger than 0.6.2.
- Support for board sizes larger than 25 x 25 has been removed. This made many of the following enhancements much easier.
- Arrow keys can be used to move through a game in analysis mode.
- Engine stays in analysis mode when moving through a game.
- Show Territory reworked to use the calculation from the engine instead of a simplified one from the GUI. Display is now prettier and can show the likelihood graphically.
- Option to show the probabilities from the DCNN as a heatmap.
- Analysis Window providing in-depth display of the move evaluations.
Lines can be clicked to show the Principle Variation graphically.
- Windows DPI Scaling can be enabled or disabled via the settings menu.
- Dialogs should now fit better when using nonstandard screen or font sizes.
- Engine runs at lower priority so Windows stays more responsive.
- Windows XP SP2 is now supported as the minimal Windows version.
- OpenCL support is now available for the Linux GTP engines.
Leela 0.6.2 (2016-06-04)
- Deep Learning DCNN for move pruning during search (+6 stones strength).
- Added OpenCL version, running the DCNN on the GPU.
- Reworked search algorithm for Deep Learning mode.
Leela 0.4.6 (2016-04-07)
- Doubled size of pattern database and retuned move prediction.
- Fixed a bug introduced in 0.4.x that severely degraded life and death assessment.
- Other playout fixes improving life and death reading.
- Total playing strength improved by about half a stone.
- Dialogs will now render properly on high-DPI displays.
- Installer no longer requests administrator rights (no UAC prompt).
- Removed lite version. Full version is now free.