# The correct way to state the avalanche problem (#1)

Jeremy Jones has been making a lot of sense on how to pick lines in recent post. There’s one important point I’d like to add on the avalanche part : choosing a line and engaging into it are two seperate problems. And as a math guy, I like to set my probabilities problem right.

So the first part is choosing wether you want to go or not. I insist on the want thing, the threshold for acceptable risk is purely personnal, there’s no such thing as a right degree of risk. That being said, choosing if you want to go is a three step process :

• check the local avalanche report
• check the particular situation of your line according to it (exposure, snowload, wind …)
• check if YOU are all ok, mentaly and physically. (I’ll get back on that in a later post)

In this part you’re trying to judge the mountain, trying to beat her poker face. The whole point of the process is to determine wether you’re playing head or tail or the one billion lottery. The great prize here being death.

Ok, so at this point you’re either riding away on groomers or saying “Chances are it is a safe enough line”. “safe enough” rather than “safe”, because it’s your acceptable risk. “Chances are it is” rather than “it is”, because you might have picked a very dangerous line without any means to know it. It’s not your fault, the snow cover’s poker face can be really hard to beat sometimes.

There are things you can do when you’re in this situation. There also things you can do to minimize the risk of ending up in such a situation in the first place.  (image whitelines.com)

So you’re on top, you decided you’re going : Forget all of the above decision process ! (except the fact that you’re going of course). It’s possible to loose at head or tail, it’s possible to win the national lottery. So you always ride like there’s gonna be an avalanche. No matter how safe you think it is. Think of exits, think of where in your run it would be smart to stop, where you should rather try to rush down. An old guide (hence a good one !) told me once «Imagination will save you in the mountain».

It sounds a bit of a heavy stuff, killing the fun. It just becomes second nature in no time, and it’s very fast. Just those two steps : what kind of lottery am I playing ? What if I “win” anyways ? Everything other reasoning on odds and probabilies is bullshit, especially those involving guts, instinct or any kind of bad feeling.

Ride safe guys !

Wonkish note : The thing at stake here is called prior probabilities in a bayesian network (check the wikipedia page). It means we want to guess before the event actually happens. And that’s very different from judging after the avalanche happens. I mean the numbers truly are different from a mathematical point of view.