The Superhero Database Classification number, or SHDB Class, is a number that represents the overall 'power' of a character. All traits of a character are used for calculating the Classification.
What it DOESN'T mean
This doesn't mean that a higher class would always beat a lower class character. But the bigger the difference in Class is, the more obvious it is who'll win in a fight.
How is this calculated
( INT^1.3 + (STR*0.5 )^2 + (SPE*0.5)^2 + DUR^1.6 + (POW + (SPS*SPL))^2 + COM^1.8 ) ^ TIER
Super Power Score and Level
Every Super Power has a score (SPS) that is used to calculate the Class. Each Super Power also has 3 levels (SPL). The level is set when connecting that Super Power to a character. The level determines the final score, of the Super Power, being used in the calculation.
Strength: Batman is very strong and can lift a car which is 500 Kgs
Speed: Nightwing is way faster and can jump on moving trains easily
Durability: Batman is never tired and can run quite fast for a lot of amount of time
Wepoanry: Batman has stronger bombs and guns than Nightwing
Intelligence: Batman is a bit more intelligent
Combat: Batman taught Nightwing many tricks in combat and has some tricks that Nightwing cannot beat
Hence, Batman wins