I did and I would point out that while they use checkpoints, the training curves indicate this is not necessary, and what I meant is that they do not use the u

I did and I would point out that while they use checkpoints, the training curves indicate this is not necessary, and what I meant is that they do not use the usual self-play (and evolutionary) mechanism of checkpoints from throughout the training history which is necessary to combat catastrophic forgetting (and which apparently wasn't enough to stabilize Zero on its own as it is the single most obvious thing to do but Silver notes all the pre-Zero self-plays diverged until they finally came up with that of MCTS supervision). The checkpoint mechanism there appears no more necessary than checkpoints in training any NN - it's critical to avoid a random error or bug wasting weeks of time but does not affect the training dynamics in any important way.