Time evolution of selected quantities during the disk passage of NOAA 11158. From top to bottom: the (a) total helicity (H_V), (b) helicity of the current-carrying field (H_J), (c) helicity ratio (|H_J|/|H_V|), and (d) the energy correlation (C_erg) of the pair (A, ∇ × B). (Dis-)Qualifying values are indicated by (empty) filled black squares. The black curve represents a fitting to the qualifying values onto a uniform (12-min) time cadence. Solid and dashed vertical lines mark the GOES start time of X- and M-class flares, respectively. Blue (red) indicates an confined (eruptive) flare type.