I recommend listening to a couple podcast episodes relating to this issue. The first is
episode 121 of the Hunt Backcountry Podcast "Grizzly Bear Survival and Defense Tactics", and the second is
episode 081 of Hunt Talk Radio with Randy Newberg, "Todd Orr on Grizzly Attacks..."
I found good information in both episodes, although the Randy Newberg episode is more story telling and more ramblings. But still good stuff to listen to.