  We introduce an improved mass formula for the nucleon and delta resonances
and show how it emerges from AdS/QCD in a straightforward extension of the
'metric soft wall' gravity dual. The resulting spectrum depends on just one
adjustable parameter, characterizing confinement-induced IR deformations of the
anti-de Sitter (AdS) metric, and on the fraction of 'good' (i.e. maximally
attractive) diquarks in the baryon's quark model wave function. Despite its
simplicity, the predicted spectrum describes the masses of all 48 observed
light-quark baryon states and their linear trajectory structure with
unprecedented accuracy.
