Relations between solar wind speed and complexity parameters: All curves are smoothed by a yearly running average of the values of γ and D (black curves) on the left and v_p (blue curves) on the right. Horizontal dashed black lines indicate the limit γ_un between chaotic and stochastic information in (a) and the upper half of the reversibility range over the continuous black line in (b). Vertical dashed blue lines delimit solar cycles 23 and 24. The colored blocks represent the phases of the solar cycles. The time period covers from 5 Aug. 1995 to 29 May 2019.