[erikbern]

I think that's pretty useful approach. It's kind of similar to Hinton's latest work on model compression: http://www.ttic.edu/dl/dark14.pdf

The problem with deep models is when you end up having more than 1 hidden layers, you have a big matrix multiplication to get between the layers. If your hidden layers are a few thousand units, that's still pretty slow. Doing things in minibatches or on the GPU speeds it up significantly, but I'm guessing it's still orders of magnitudes slower than whatever Stockfish uses

[thomasahle]

Sure, the second layer would have to be very sparse. That makes sense since most multi-piece 'chunks' are not really that interesting.