Thanks I think I kind of understand. The yellow numbers are the number of gear teeth. What are the white numbers? The gear ratio?

If that is the case then it looks like the only thing you lose is 10.5 of whatever the white number is when going up a steep hill, and 2.2 when going downhill.

Pretty cool. So the bottom line is that going 1x9 gives you the same RANGE but the jumps between gears are larger. Correct?