Scatter plots of X-ray peak fluxes of solar flares (0.1–0.8 nm) vs respective initial velocity of CMEs: (a) average velocity-STEREO, (b) maximum velocity-STEREO, (c) average velocity-SOHO, (d) maximum velocity-SOHO. The open symbols represent disk events (longitude −20 < L < 45) and filled symbols represent west events (Longitud >45). There is one east event, on 31 August 2012 (longitude < −20; in yellow). This is the only event in our sample analyzed by STEREO-B as it exhibited good quality.