It's a fear thing, JC. You always want to lead everything, which means your belayer is stuck looking up at your hiney, wondering if you pop how much damage it will cause. ie.JC on Sqareblock with 80' ground fall.
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On certain climbs the lead may be more dangerous for the second.
For the belayer it's not just beware of "FALLING ROCK" but also "FALLING ASS"!
Ask KC'