>No, I assure you that stockfish definitely does not look "all the way down (ie to states where the game is over)" in most positions, even with pruning - that would take too long. It uses a static evaluation function to evaluate positions without searching down the tree further
Ehh alright, it calculates the value of a node exactly (or exactly assuming its evaluation function). MCTS does not.
To be clear, what I meant, that you pulled out of context is that Minimax requires an exact calculation of the value of each child before choosing the best and returning it, this requires either simulating every possible game, or an evaluation function (depth-pruning). MCTS uses monte-carlo methods to estimate the best paths instead of trying all of them naively. At t=infinity, MCTS is equivalent to Minimax, because it will try all nodes. But it can run in time constrained systems better because it picks a much smarter order to run in.
>You described the "Monte Carlo" part of MCTS but not the "Tree Search" part. It's right in the name! See for example the first paragraph on page 20 of https://gogameguru.com/i/2016/03/deepmind-mastering-go.pdf, which clearly describes AG constructing a search tree.
yes. That has nothing to do with minimax though.
Which is what I said. AlphaGo uses pruning. AlphaGo doesn't use minimax with or without pruning, it uses MCTS (with pruning).
Ehh alright, it calculates the value of a node exactly (or exactly assuming its evaluation function). MCTS does not.
To be clear, what I meant, that you pulled out of context is that Minimax requires an exact calculation of the value of each child before choosing the best and returning it, this requires either simulating every possible game, or an evaluation function (depth-pruning). MCTS uses monte-carlo methods to estimate the best paths instead of trying all of them naively. At t=infinity, MCTS is equivalent to Minimax, because it will try all nodes. But it can run in time constrained systems better because it picks a much smarter order to run in.
>You described the "Monte Carlo" part of MCTS but not the "Tree Search" part. It's right in the name! See for example the first paragraph on page 20 of https://gogameguru.com/i/2016/03/deepmind-mastering-go.pdf, which clearly describes AG constructing a search tree.
yes. That has nothing to do with minimax though.
Which is what I said. AlphaGo uses pruning. AlphaGo doesn't use minimax with or without pruning, it uses MCTS (with pruning).