Every grade at some point is considered the hardest, but what I suspect you're referring to is the Yosemite Decimal System [1] which postulated 5.9 as the harde

Every grade at some point is considered the hardest, but what I suspect you're referring to is the Yosemite Decimal System [1] which postulated 5.9 as the hardest grade possible (5.1 and 5.10 are the same from a numeric point of view). I always thought the Australian system (start at one and go up) made the most sense, but the context the the British grading system [2] provides is wonderful. [1]: http://en.wikipedia.org/wiki/Yosemite_Decimal_System http://en.wikipedia.org/wiki/Yosemite_Decimal_System [2]: http://en.wikipedia.org/wiki/Grade_(climbing)#British http://en.wikipedia.org/wiki/Grade_(climbing)#British