Motocross is the devil. I run 12 hour enduro races, you tend to get a little sloppy after a few hours. This is over 15 years of riding/racing, 3 variants of motorcycles. My record holder involved a drunk in a truck, was not on the track.
Its just a law of averages. It's not a matter if "if", but "when" and "how severe".
In the past 12 months, I personally had 2 friends go (1 motocross, 1 supermoto) in competition. One on the street, not counting my street excursion that put me in a trauma center for 3 weeks on life support.
