I have created a new map of R1a-M458, a lineage which I associate with the Corded Ware expansion and which peaks in West Slavic countries today. The Underhill et al. 2014 paper provided a rough distribution map of R1a-M458, but I wasn't satisfied by its accuracy (it is auto-generated, not hand-made like mine). For example I have drawn the exact data for the Caucasus and the Volga-Ural region. I have also recalculated some percentages based on my Y-DNA frequencies. It does not affect a lot of regions, but in some cases the gap is considerable, and Underhill et al. had far fewer samples. E.g. for Hungary I have over 800 samples totalling 29.5% of R1a, while Underhill et al. had 18.6% of R1a out of 113 samples.