Time evolution of the magnetic flux, ϕ, and the GOES soft X-ray flux for the ten ARs under study. Quantities for ARs productive of large eruptive and confined flares are shown in the left and right columns, respectively. Black curve represents the average of the magnetic fluxes calculated from NLFF bottom boundary fields based on enhanced (standard) divergence freeness as indicated by squares (bullets). The gray shaded areas mark the spread of ϕ. Blue curve shows the evolution of GOES soft-X ray flux. Vertical bar indicate the impulsive flare phase.