First order branching factor is less important than you might think.
You could setup a game of Nim: https://en.wikipedia.org/wiki/Nim with much higher branching factor vs Go, but because you can trivially separate a winning moves vs. losing moves those branches become irrelevant in Nim. AKA, if there are 2,000 winning moves then they are all equivalent.
You could setup a game of Nim: https://en.wikipedia.org/wiki/Nim with much higher branching factor vs Go, but because you can trivially separate a winning moves vs. losing moves those branches become irrelevant in Nim. AKA, if there are 2,000 winning moves then they are all equivalent.