why?

I've been in two serious crashes and each time I instinctively tucked in and held onto my bars tight. I landed on my right shoulder and upper arm area, rolled, bike hit the ground as I rolled over and I stopped. If I didnt hold onto my bars, I would have kept rolling and taken all of the impact on my body. I twisted my ankle from being strapped in the first time and the second time no injuries besides road rash and bruises on my arms/shoulder (and a ripped up t-shirt).

I think a tuck-roll along with your bike is the safest way to fall.