I agree with what Shelt has pointed out.
As far as statistics go, I've never seen the document with the stat. I've talked to the Police and RCMP here in Canada and they don't keep stats to the level of "it went to the ground". Stats are easy to pull out of the air. A better way of compiling stats in this circumstance might be to look at the street fights in You Tube and Google Video. Most fights in that circumstance seem to end on the ground when people get hit or the fight is over.
With more people watching UFC and taking BJJ the chance of going against someone who might get into your guard increases.
Most people have a fear of the ground, during falling or while on their backs. Being in control of the situation and knowing you are on the ground if it happens is a powerful tool. I don't want to stay on the ground, but if it happens by intention, accident or someone forces me on the ground I want to be able to handle the circumstance.
Ground game should provide you...
1) Awareness of your environment when on the ground
2) Awareness of what is possible when you or your opponent is on the ground
3) Ability to reduce the blow from falling (break falls and tumbling)
4) How to combativly get off the ground
5) How to control the situation if you are on the ground
Regardless of statistics, to be an all around good martial art athlete, the ground position is key.
I'm a clinch lover not a ground fighter, but I still train hard in my ground work!
IMHO, some fights end up on the ground because two people get tangled in the clinch and neither can manage the position so they trip and fall and go *BOOM*.
In a fight, unless I am 100% control of the environment (or at least 98%) and know my opponent I won't go to the ground with my opponent - it doesn't mean I won't take him to the ground.
When I do go the ground in an uncontrolled environment - I get off the ground as soon as possible. Even if its a controlled environment, I'm getting off the ground as soon as possible once I create a controlled situation over my opponent.
Cheers,
Bryan
P.S. I'm going Maple Syrup hunting this weekend. I will send some to Hawaii in a care package!