- Technical Proficiency
- Listenability
- Solo Orgasm Faceability
- Flow
- Length
- Jizzability
- Awesomeness
Yes, these are completely arbitrary.
Some explanations of what each entails:
Technical Proficiency ranks various guitar playing techniques that can be hard to pull off. Some, of course, much harder than others. These include but are not limited to: Hammer ons/pull offs, vibrato, tremolo, harmonics, tapping, sweeping, harmonisation. For the record, two songs got the maximum 100 marks for technical.
Listenability ranks how nice the solo is on the ears. Some of the greatest solos of all time had just a great deal of vibrato but not much other technical wankery, and this is what that ranks. How "nice" the solo is.
Solo Face Orgasmability ranks how well a guitarist could guitar solo face orgasm to the solo. This is probably one of the three most arbitrary rankings. Basically if anything has a pattern of three semiquavers and then a crotchet, with whammy bar, that's soloface orgasm.
Flow ranks how well the solo fits into the song. Of course, fitting too well is a bad thing, for example, sweeping around in the pattern of a chord progression is pretty damn boring, but technically good. There are a few solos on this list like this.
Length is pretty obvious. The longer a solo is, the cooler it is.
Jizzability is how likely you are to jizz your pants because of the solo. Also known as Finger Explodability, based on how likely it is your fingers would explode playing it.
Awesomeness is just a ranking of how good it all sounds together.