Good books to learn Combinatorial Game Theory?

Question

I am currently doing my IB Diploma and we are supposed to make an extended essay on a subject of our choice- and i chose math. my research question is- "how to derive a perfect strategy to always win at the game of Nim?" - it has already been done- i know- but they aren't expecting anything groundbeaking from us- we're 17 year olds. anyway i don't have much knowledge in CGT and i need to know which books could be suitable for my essay. obviously it should include the study of zero sum, two player determnistic games,etc.
thanks for the help

Answer 1

I think the classics of Combinatorial Game Theory are "On Numbers and Games" and the multi-volume "Winning Ways for your Mathematical Plays".

These go much further than Nim, which has a fairly simple algorithm for perfect play.