Hotspot overlap of well-resolved crossovers. Hotspot usage of Asian and CEPH families. Using recombination prediction intervals resolved to 30 kb or better, we counted the proportion that overlapped with known hotspots (white plus blue; 82%). To find a rough estimate for the proportion of these predictions where the recombination really occurred in a hotspot (white; 72%), we performed random perturbations. Our results show far more recombination occurring in historical hotspots than has been previously reported. Asian and CEPH families had almost identical hotspot usage.