Trevor submitted a brilliant entry to the Teddy Rocks Maths Essay Competition which he turned into a video on his YouTube channel that he kindly asked me to introduce…

The golden ratio appears unexpectedly in a game of removing stones, similar in style to NIM. It is a game played in the ancient Chinese, and there is also a variant called the Wythoff’s game. The proof of the winning strategy is related to the Beatty’s theorem and is shown in detail in this video.