In reply to Paul Sagar:
Indeed, a really nice article.
as for the grade one climbs tge first time they try climbing. Well, V1 to V3 is pretty spot on or common. Outliers exist, such as one keen teen who started tickin’ V6s (and the grades weren’t soft at that place, I often have more change of flashing a V5 outdoors than a V4 at that gym).