New theories beyond the Standard Model generically predict exotic resonances appearing at or above the weak scale. If these resonances decay into jets, formidable QCD backgrounds must be overcome in order to observe these signals at the LHC. I will introduce a new observable that is effective at tagging dijet resonances from several SM and beyond-SM processes, improving the precision with which we study SM couplings and enhancing the sensitivity to new physics. This observable is particularly well-suited for searches dominated by systematic uncertainties, as will be true for many analyses in the high-luminosity running of the LHC.