Overall long-term preflare time evolution of selected coronal quantities deduced from superposed epoch analysis. Median values were computed separately for the subsets of confined (blue) and eruptive (red) flares. Covered is the time period from −48 hours to +6 hours around the flare start time (black dotted line at time t_start = 0). The 24 hours used for selection of qualified events is marked by the gray-shaded area. Numbers in brackets indicate the ratio of confined to eruptive flares within the tested sample. Left column: Superposed epoch data of (a) the total unsigned flux (ϕ_m), (b) total magnetic energy (E), (d) total unsigned magnetic helicity (|H_V|), (f) free energy (E_F), and (h) unsigned helicity of the current-carrying field (|H_J|). Right column: Superposed epoch data of the (c) free-to-potential magnetic energy ratio (E_F/E₀), (e) helicity ratio (|H_J|/|H_V|), (g) flux-normalized total helicity ($|H_{\mathrm{V}}|/{\stackrel{\sim }{\varphi }}^2$), and (i) flux-normalized helicity of the current-carrying field ($|H_{\mathrm{J}}|/{\stackrel{\sim }{\varphi }}^2$). Horizontal black dotted lines indicate respective critical values. The red and blue diagonally shaded regimes are bound by the upper and lower quartiles of the respective distributions.