Mean hourly variations (one-hour time gradient) in the overall preflare time evolution. Numbers in brackets indicate the ratio of confined to eruptive flares within the tested sample (S​_SEA). Mean values for confined (blue) and eruptive (red) flares, computed from the synthesized preflare time profiles are shown. The shaded regimes indicate the standard deviation. Covered is the 24 hours time period prior to the flare start time (t_start). The top panels show signed variations in the time evolution of the (a) unsigned magnetic flux (ϕ_m), (b) total energy E, and (c) unsigned total helicity (|H_V|). Positive/negative values indicate an/a respective increase/decrease over time. The bottom panels (d–f) show the respective unsigned variations.