Measures of the quality of the optimized phases for the strongest reflections selected in the search. The measures were calculated using the map correlation coefficients (equation 2) of the optimized phases (φS) and the known phases (φC). Each dot represents a set of phases yielding a certain skew value of the density map and a certain value of map correlation. The filled dots show the map correlation coefficients of the centroid phases calculated from a group of phases with similar skew value. All plots show the results from five independent runs, with a square marker representing the original centroid phases φB and a diamond marker representing the optimized phases φS selected as the output of the search process for (a) the 20 strongest reflections, (b) the 30 strongest reflections, (c) the 100 strongest reflections and (d) the 500 strongest reflections.