Where Does The 5 Come From? : Climbing Rating Systems

You’ve probably heard it before. “He climbs 5.12!”, or “That route is a 5.7.”

Where does the 5 come from?

The mountaineering difficulty rating system was developed in the ‘20s to help those seeking adventure to stay within their ability level, which subsequently has helped keep people safe and informed in the backcountry ever since. This rating system has taken different forms over the past 100 years. It has been upgraded, reinvented, and honed for different aspects of mountaineering and, just like language, has evolved differently depending on the region using it.

Most American rock climbers are familiar with the mountaineering difficulty rating system known as the Yosemite Decimal System (YDS). At the most basic level, the YDS divides backcountry travel into 5 classes, each level indicating a more difficult terrain. Class 1 can be described on hiking on fairly flat ground. Class 2 indicates simple scrambling and rock hopping. Something where you might need your hands to support yourself. Class 3 is scrambling. You are on rough terrain where you need to use your hands for balance. Class 4 is simple climbing. Sometimes the climbing can be exposed and a rope may be used. An unprotected fall in this terrain could result in injury or fatality. Class 5 is what most people think of as rock climbing, and it is the class in which we rate the difficulty of rock climbs. It is climbing a steep surface where ropes, belaying, and protection are necessary.

The YDS took the original “class” rating system that was not quite suitable for the sport of rock climbing and added a sub-class system to further explain a specific climbing routes difficulty. It designated a difficulty rating of 5.1 to 5.9. This worked up until the 60’s when the sport was evolving to a more athletic pursuit and climbers were pushing the limits of what was considered possible. They were confronted with a problem. “If climb A is rated 5.9 and climb B is obviously harder.. what do we call it?”. Class 6 would imply a whole different category of moving through the mountains, which was not quite adequate, so they simply kept increasing the number. Climb B from our example became 5.10. Now we have ratings up to 5.15 with some considering the possibility of 5.16. Climbs that are rated 5.10 and up were given another subcategory of a,b,c, and d (or sometimes just + and -) to even more accurately describe the nuances of a climbing routes difficulty.

That is where our rating system is at today. It is important to remember, however, that rating systems are completely subjective. The same rating in one area can feel completely different in another area, which means it is a good idea to familiarize yourself with the difficulty of a new climbing area before you jump on a climb that is towards your rating limit. Remember, the rating system is there so you don’t get in over your head, not so you can define yourself and others!