GUARD: Grading Using Aggregated Ranked Difficulty

This page describes a new method for grading rock climbing routes. Results are provided for popular sport climbing routes in South Africa.

The trick is to have people rank routes in order of difficulty rather than explicitly assign number grades.

An aggregator then creates an overall ranking list that best explains the individual rankings. (Some maths + programming.)

This stops people from being anchored by the commonly-held bizarre notion that the given-grade is somehow an inherent property of the route rather than a guidebook. And also removes the emotional issues people seem to have about grade inflation and so forth --- as the obfuscating notions of grading hard/soft, sandbagging, appeasing girlfriends with cheap grades &c &c disappears.

Lastly grades can be fitted to the overall ranking list to create a much more objective estimate of grades than competing methods (e.g. average grade given on

(You can also see which routes varied the least/most in terms of opinion of difficulty and all sorts of stuff like that.)

Summary: Forget about numbers. Rank routes. Then assign the numbers afterwards.

By having several climbers participate, individual inaccuracies and personal strengths + weaknesses tend to cancel out. Not thinking about grade helps concentrate on the problem at hand: how hard the routes are with respect to other routes.

(Saying A is harder than B rather than B is harder than A is usually not ego-driven: with number grades it's often different.)

An Aggregate List is formed from the individual ranking lists. This is the list that is in best agreement with all individual lists. (A computer program is used to minimise sum of pairwise rank disagreements between all individual lists and the Aggregate List.)

I got the following climbers to provide ranking lists: Alan Hills, Garron Fish, Harry Crews, Jacques Redelinghuys, Jimbo Smith, Karen Varga, Keith Forbes, Paul Brouard, Paul Prozesky, Phlip Olivier, Richard Halsey, Steve Bradshaw, Cormac Tooze, Adam Ludford.

A number grade is assigned once the Aggregate List is formed. Number grades are interpolated based on rank. The median rank of routes for each number grade gives a fair measure of what each number grade is considered to be (using data). I think the computed order (that is, rank) is however more interesting than the final numbers.

The premise is simple: a route cannot be graded harder if it ranks easier.

Here is the Aggregate List, easiest to hardest:

< 24, All Mine, The Mine, AH KF PO
< 24, Sterling Silver, Silvermine, CT KF
< 24, Jono Gordon's Route, Silvermine, CT KF
< 24, Bolt Your Bitch, Montagu, AH KV PO
< 24, Shagadelic, Montagu, AH PP PO
< 24, Goonie Goo Goo, Oudtshoorn, AH JS KV KF PB PO
< 24, Walk on By, Montagu, JS KF PO
< 24, Miss Mckinley, Boven, AH PB PP PO
< 24, Sickle Moon, The Mine, AH CT GF JS KV KF PO
< 24, Fin, Fang, Fly, Oudtshoorn, AH JS PO
< 24, The Neuromancer, Montagu, AH GF JS KF PP PO
< 24, Rude Bushman, Boven, AH JS KV PB PP PO
< 24, The Church of Frederico, Montagu, AH JS KV PO
< 24, Phallic Mechanic, Oudtshoorn, AH JS KV PO
< 24, The Jester, Montagu, KF PP PO
soft 24, Trance Dance, Silvermine, CT KF
soft 24, Rock-Chucka-Chick, Boven, KF PP PO
soft 24, Rattle and Hum, Montagu, JS PP PO
soft 24, Cactus Palace, Waterval Boven, KF PP
soft 24, Voices, Montagu, CT KF
soft 24, Jimmy and the Big Boys, The Mine, AH GF JS KV KF PO
soft 24, Cleinous Hing, Montagu, AH PO
fair 24, Eddy of Bovidence, Montagu, AH CT JS KV KF PP PO
fair 24, Rapscallion La Codge, Oudtshoorn, JS PP
fair 24, Behr Hug, Oudtshoorn, AH GF JS KV KF PO
fair 24, Women Ain't Nothing but Trouble, Waterval Boven, KV PP
fair 24, Atomic Aardvark, Boven, JS PB PP
hard 24, Cyberpunk, Montagu, AH JS KV KF PP PO
hard 24, Hunks on the Ceiling, Truitjieskraal, KF RH
hard 24, Freak On, Boven, AH JS KF PP PO
hard 24, Beautiful Day, Montagu, AL PO
hard 24, Swan Lake, The Mine, AL AH GF JS KV KF PP PO
soft 25, Lord Melbury, Silvermine, KF RH
soft 25, Brother Bear, Oudtshoorn, AL AH JS
soft 25, Red Guitar on Fire, The Mine, AL AH GF JS KV KF PB PP PO RH
fair 25, First Wave, Montagu, AL AH JS KV KF PP PO
fair 25, Jambo, Boven, PP RH
fair 25, Madiba, Montagu, GF JS KF PO RH
fair 25, Holy Moly, Montagu, AH KV PO
hard 25, Dungeons and Dragons, Boven, AL AH
hard 25, Hueco Punks, Truitjieskraal, KF RH
hard 25, Big Foot, Oudtshoorn, AH JS PP PO RH
soft 26, Silver Streak, Silvermine, KF RH
soft 26, Paws, Oudtshoorn, AL AH HC JR JS KV KF PB PP PO RH
fair 26, Delete Button, Montagu, AL RH
fair 26, Thruster, Montagu, AL AH JS KV KF PB PP PO RH
hard 26, Leap Tide, Montagu, AH JR PO RH
hard 26, Sid Vicious, Oudtshoorn, AH JS KV PP PO RH
hard 26, Half Quick, Oudtshoorn, HC RH
hard 26, Digital Bitch, Montagu, GF JS KF PP PO
soft 27, Chocolate Eclair, Boven, AL AH HC PO
soft 27, Pocket Rocket, Kalk Bay, PB PP
soft 27, Wings of Glory, Kleinmond, AH PO
soft 27, Menopaws, Oudtshoorn, JS PP PO RH
soft 27, The Optimist, Montagu, AL AH GF JS KV KF PO
fair 27, Hell Yeah, Boven, AH HC
fair 27, Simply Irresistible, Montagu, AL AH HC JR JS KF PO
fair 27, Lost Safari, Oudtshoorn, JS RH
fair 27, The Happy Hooker, The Mine, HC KF
hard 27, Johnny Rotten, Oudtshoorn, AL AH JR JS KV PB PO RH
hard 27, Route 66, The Hole, JS KF
hard 27, Neanderthal Rex, Montagu, AH GF JS KF PO
hard 27, Lotter's Desire, Boven, AH HC JR JS KV KF PB PO RH
soft 28, Winston, Kleinmond, AH PO
soft 28, All That Glitters Is Gold, The Mine, GF HC JR JS KV KF PP PO
soft 28, Rad and Bad, Montagu, JS KF PO
fair 28, Daze of Thunder, Montagu, AH GF HC JR JS KV KF PB PO RH
fair 28, Whoa She Poopie, Montagu, HC JR JS KV PO
fair 28, Trainspotting, Silvermine, AH PO RH
fair 28, Virus, The Hole, JS KF
fair 28, Burning Chrome, Montagu, JS KF PO
hard 28, Eraserhead, Boven, HC KV PB RH
hard 28, A Gift of Wings, The Mine, AL AH HC JS KF PP PO
hard 28, Espionage, Kalk Bay, AH PO
hard 28, Firestarter!, Montagu, AH HC JS KF PB PO SB
hard 28, Hot Toddy Benson, Montagu, HC JS
hard 28, Going Going Gone, Oudtshoorn, AH HC PO
hard 28, Hard Play, Oudtshoorn, HC PO
soft 29, Monkey Pump, Montagu, AL AH GF HC JS KV KF PB PO SB
soft 29, Seven (Wimp Finish), Oudtshoorn, AL AH HC JS KV PB PO RH
soft 29, Snapdragon, Boven, GF HC JS KV PB PP RH SB
soft 29, Paragon, Wave Cave, JS SB
soft 29, The Shouting Stage, Montagu, HC JS
soft 29, Mono, The Mine, JS KF PO
fair 29, A Gift of Gold, The Mine, KF PO
fair 29, Monster, Boven, AL BW HC JS PB PO
fair 29, Cool Like That, Montagu, AL AH GF HC JS KV KF PB PO SB
fair 29, Twisted Steel and Sex Appeal, Montagu, AH JS PO SB
fair 29, Ben Dover, Montagu, AH HC JS
fair 29, Point Break, Montagu, AH HC JR JS KV KF PO SB
hard 29, Golden Eye, Kalk Bay, AL JS KF PO
hard 29, El Nino, Oudtshoorn, BW HC JS KV PB PO RH SB
hard 29, Mama Africa, Oudtshoorn, HC JS
hard 29, Hypoxia, Montagu, BW GF JS KF PB PO SB
soft 30, The Vice, Oudtshoorn, HC JS
soft 30, The Activist, Montagu, AH BW HC JS KV KF PB PO SB
soft 30, Up for Grabs, Oudtshoorn, AH HC JS PB PO SB
fair 30, Jack of All Trades, Boven, HC JS SB
fair 30, Catholic School Girls Rule, Montagu, JS PO
fair 30, Strange Days, Montagu, HC JS SB
> 30, Kohler-Turkstra, Oudtshoorn, HC JS SB
> 30, Short Circuit, Oudtshoorn, HC JS PB SB
> 30, Switchbitch, Montagu, AH JS PO SB
> 30, The Beast, Boven, AL JS
> 30, Godzilla, Boven, HC JS
> 30, Barricade, Wave Cave, PB SB

Initials indicate who ranked the route. Routes with at least two opinions are shown above.

You can help by creating your own list in this Google Doc. Or just email it to me:

The more climbers and the more routes ranked, the better.

Later I might add a rant about the inane, banal, and idiotic comments people make on the subject of grading rock climbing routes---what drove me to embark on this project. I may even describe the technical details of the algorithm at some stage... Other potential topics include: (1) how we could test accuracy, (2) methods that actually are better in principle, but for which data collection is likely far too onerous.

Comments? Queries?

Boulder grades