attempt to compare difficulties of rock climbing (YDS, Hueco, French). Not equality, but level of difficulty/reward.

grades.yml

0:
  yds: <5.5
  hueco: VB
  french: <2+
1:
  yds: 5.5
  hueco: VB
  french: 3-
2:
  yds: 5.6
  hueco: VB
  french: 3
3:
  yds: 5.7
  hueco: VB
  french: 4
4:
  yds: 5.8
  hueco: VB
  french: 4
5:
  yds: 5.9
  hueco: VB
  french: 4+
6:
  yds: 5.10a
  hueco: V0
  french: 4+
7:
  yds: 5.10b
  hueco: V0
  french: 5
8:
  yds: 5.10c
  hueco: V1
  french: 5+
9:
  yds: 5.10d
  hueco: V1
  french: 6a
10:
  yds: 5.11a
  hueco: V2
  french: 6a
11:
  yds: 5.11b
  hueco: V2
  french: 6b
12:
  yds: 5.11c
  hueco: V3
  french: 6c
13:
  yds: 5.11d
  hueco: V3
  french: 7a
14:
  yds: 5.12a
  hueco: V4
  french: 7a+
15:
  yds: 5.12b
  hueco: V5
  french: 7b
16:
  yds: 5.12c
  hueco: V6
  french: 7b+
17:
  yds: 5.12d
  hueco: V7
  french: 7c
18:
  yds: 5.13a
  hueco: V8
  french: 7c+
19:
  yds: 5.13b
  hueco: V8
  french: 8a
20:
  yds: 5.13c
  hueco: V9
  french: 8a+
21:
  yds: 5.13d
  hueco: V9
  french: 8b
22:
  yds: 5.14a
  hueco: V10
  french: 8b+
23:
  yds: 5.14b
  hueco: V11
  french: 8c
24:
  yds: 5.14c
  hueco: V12
  french: 8c+
25:
  yds: 5.14d
  hueco: V13
  french: 9a
26:
  yds: 5.15a
  hueco: V14
  french: 9a+
27:
  yds: 5.15b
  hueco: V15
  french: 9b
28:
  yds: 5.15c
  hueco: V16
  french: 9c