You can tell a lot by the forearms. In Germany I hired 2 climbers with small forearms. Scottish runts no less. They weren't much good at trees, but the sure could lift a pint.
Funny that, worked in D.C. a few years years back, started with a company, a week later me and Carlos are introduced to our new climber 'X'. Talked himself up bigtime, real treeclimbing hero, turned out to be a major bullsh*tter.
He volunteered to distmantle a 120ft Tulip on his 1st day, came down after 45 mins nearly crying.
Where was he from? Austin, Texas no less.
Had to teach the guy from scratch.
On a positive note he was a cool guy, small forearms as well.