"Mature" free soloists typically prioritize mental mastery over raw risk-taking:
When using tiny "crimp" edges, "mature" or highly trained climbers often wrap their thumb over their index finger to increase power and stability. free solo mature thumbs
For veteran climbers, the thumb acts as a "secret weapon" to provide stability on minuscule holds where a standard grip isn't possible. 1. Thumb & Hand Techniques for Experienced Soloists free solo mature thumbs