I don't like the framing. AlphaZero is just a very refined and efficient form of brute force. Precomputing weights obtained by brute force doesn't make the overall enterprise not brute force anymore.
If AlphaZero is brute force than any use of a non-exhaustive planning mechanism (pruned MCTS in this case) is brute force which is honestly ridiculous. Search and planning have a long history in both computer science _and_ neuropsychology because that is what we call the methods that are more efficient than brute force at the expense of some accuracy.
There are some problems with the article but it isn't that AlphaZero is just some overhyped brute force algorithm.
On a related note, AlphaZero used quite a lot of processing power - even with the optimizations, if it had to run on human hardware it would be pretty worthless.
It ran on a single machine with four TPUs. In a few years with a few more optimizations, I can imagine an equal strength implementation on a handheld chess computer.
If you're talking about training hardware, the correct comparison is against the processing time used by all serious human chess players through history because an apples to apples comparison would have both training from scratch (just the rules).
>One way to speed up a brute-force algorithm is to reduce the search space, that is, the set of candidate solutions, by using heuristics specific to the problem class.
The term brute force is clearly used for algorithms besides for ones that literally try every possible solution.
Want more? I found http://www.cs.cmu.edu/~ab/Desktop/15-211%20Archive/res00038/... from a google search, lecture notes which says
>Minimax is pretty slow even for a modest depth. It is basically a brute force search
As we can see, brute force can be used as a statement about how much computation is required,
Hell, here's Kasparov himself (cited in TFA as an authority) using the term for minimax https://twitter.com/kasparov63/status/867586759412068352?lan...
The term is clearly used widely to refer to more than just exhaustive algorithms.
The article portrays this as a battle between engines like stockfish, which are brute force (note that they explicitly call previous chess programs brute force, although clearly one based on your definition would be useless), against AlphaZero, which supposedly does more than brute force and has principles and insight etc. I think this gets it exactly backwards - stockfish had a lot of principles baked in by humans, as the article acknowledges, but alphazero was given 0 knowledge of chess other than the rules. Seems like this is properly viewed as a triumph of efficient algorithms over ones with principles, which is nearly opposite to the article's framing.
My reading of that sentence from Wikipedia is that this is the step by which a brute force approach is transformed into a "clever" approach. The hard part is to find valid and useful heuristics, which often also involve switching data structures in some way.
>AlphaZero gives every appearance of having discovered some important principles about chess, but it can’t share that understanding with us.
No, it doesn't have any new principles, it just has a very good system of weights.
Imagine a perfect computer that plays the game by mapping out every single move. AlphaZero is a series of optimizations that allow for an efficient but lossy simulation of such a computer. Most of the research in this area is about making an oracle more practical/more accurate estimations of the theoretically correct response. I think it's fair to call it brute force with optimizations.
The difference between AlphaZero and StockFish is that StockFish only does the latter (compute weights for features given to it by others), while AlphaZero also does the former (distill features from game state).
A good analogy is intuition. If someone says AlphaZero has developed a strong intuition for chess, I have no issue with that, and to the extent human chess is based on intuition comparison is fair. But to portray humans as having chess principles, then say AlphaZero has new ones but just can't describe them seems off.
To put it another way, humans have general intelligence and AlphaZero doesn't. At least some of the general intelligence is used for human chess play, so there is a dimension of that which AZ doesn't have.
I've played chess for many years and I've played a few games against Leela (not full strength, the early versions). I never got the feeling that I was playing a computer.
Additionally, one of the primary ways of improvement past the ~2000 level is review of master games. Most people who make it to GM level have reviewed upwards of 5,000 master games or more over a significant period of time. So they build up a similar system of "weights" in their mind for different positional features, very similarly to the way the NN would approach the problem.
Sure, AlphaZero/Leela has not obtained generalized intelligence, but within a constrained sphere (Chess, Go, etc), it has come just about as close as is possible to that.
As is evolution.