How Facebook’s AI Researchers Built a Game-Changing Go Engine

Here's the paper:

Better Computer Go Player with Neural Network and Long-term Prediction by Yuandong Tian, Yan Zhu

http://arxiv.org/abs/1511.06410

"Adding MCTS to darkforest creates a much stronger player: with only 1000 rollouts, darkforest+MCTS beats pure darkforest 90% of the time; with 5000 rollouts, our best model plus MCTS beats Pachi with 10,000 rollouts 95.5% of the time."