The pairing of homologous chromosomes in meiosis I is essential for sexual reproduction and is mediated, in part, by the formation and repair of Spo11-induced DNA double strand breaks (DSBs). In budding yeast, each cell receives 150-200 DSBs, yet only a fraction go on to form crossover products. How and why the cell initially coordinates so many interactions along each chromosome is not well understood. Using a fluorescent reporter-operator system (FROS), we measure the kinetics...