How is Alpha Zero "more human"? I have a possibly naive question about AlphaZero. I have seen it described as playing in a "more human" style than other computers, but whatever it does, it gains about 100 ELO points by doing it. Kasparov, and many others, have claimed that a strong human in collaboration with a computer will beat a strong computer (perhaps by about 100 ELO??). So an obvious question is, how would AlphaZero compare with a "centaur" combination?

Having only looked at a few games, what I notice is that most computers play wide open games that maximize their own mobility, but AlphaZero seems very concerned to limit the opponents mobility. In a human player I would describe this as a matter of style, not more or less human.
Page 5 in the paper has your answer:


  ... AlphaZero compensates for the lower number of evaluations by using its deep neural network to costs much more selectively on the most promising variations - arguably a more "human-like" approach to chess ...


"selectively" is the key word. What does that mean? Let's use this following position for our example:


  https://chess24.com/en/read/news/london-classic-5-caruana-shows-how-it-s-done




This is a recent game won by Caruana in 2017 London Chess Classic. The White bishop is under attacked, and you know you have to move it. But where?

Possibilities (not losing a piece):


Bh4
Be3
Bd2
Bc1


What was Caruana thinking?


  I felt like I would lose at some point, but when I saw, 25.Bc1 I suddenly 
  started to get a bit more optimistic about my chances. I realised my 
  position is bad, but at least I had a plan and that was really all I needed 
  for some confidence in this position. When I saw this b3, c4 the position is
  double edged and I have some chances.


This is human thinking, and a "human move". Caruana hadn't considered Bh4, Be3 and Bd2 because they "looked" bad. He had been focusing only and only on the Bc1 move.

Humans play chess very selectively, we discard unreasonable moves because we don't have time to examine all possibilities equally. 


We discard Bh4 because it release the tension on the h6 pawn
We discard Be3 because it blocks the two white rooks on the third rank
We discard Bd2 because it blocks the White queen to the king side


That's what AlphaZero trying to claim in the paper. They claim their algorithm, although slower than Stockfish, is able to selectively pick better moves than Stockfish in the search. While Stockfish is faster, it wastes time on bad moves. AlphaZero is slower, but it's more precise (like what Caruana was doing).

For example, AlphaZero might spent 80% resources on Bc1, and 20% on all other bishop moves. Stockfish might give 25% for each move (Bh4, Be3, Bd2, Bc1).