15 inch arms?
i swear to god i had 15inch arms when i was a tennis player aged 16 and never stepped foot into a gym yet.
man, with 15 inch arms, it dont matter what your wrists measure, 15 inches is basically upper arm bone with skin
16 inch here, hardly "skin and bones". To be honest I think 90% of people exaggerate and lie. 19" arms when they're in good condition are ENORMOUS.

This is my friend, around 5'10'', 19" arms. This is one hell of an arm. 17" is huge arleady...