Best Chainring Size for XC Racing

That’s interesting.
I used a mountain bike with a 10–42 cassette and a 28-tooth chain ring, and the only gap that I did not appreciate was from the 12- to the 10-tooth cog.

My current mountain bike has a 11-46 Shimano XT cassette with a bailout gear, and I don’t mind that at all. If I had to choose between a smaller chain ring and a larger gap between the easiest two gears, I’d always go for the latter.