The Council of the Great City Schools prepared this thirteenth edition of "Beating the Odds" to give the nation an in-depth look at how big-city schools are performing on the academic goals and standards set by the states. This analysis examines student achievement in mathematics and reading from spring 2010 through spring 2013; measures achievement gaps between cities and states, Blacks and Whites, Hispanics and Whites, and between other student groups; and examines district progress. This report asks two critical questions: "Are urban schools improving academically?" and "Are urban schools closing achievement gaps?" Data from this report indicate that urban school districts are making progress. Some outcomes look better than others. Trend lines differ from one city to another. Nevertheless, the data indicate overall movement and progress. In general, this edition shows that the Great City Schools continue to make important gains in mathematics and reading scores on state assessments. The study also presents additional evidence that gaps are narrowing between urban districts and states. As with other reports in this series, the findings in Beating the Odds XIII are to be interpreted with caution. The nation does not have an assessment system that allows us to measure progress relative to the same standard across all school districts in the country. The Council of the Great City Schools is addressing this weakness through the Trial Urban District Assessment (TUDA) of the National Assessment of Educational Progress (NAEP), and hopes this concern will be further mitigated by the implementation of the common core assessments. For more than a decade, the Council has produced this report on how its major city school systems are performing on the state assessments devised to boost standards, measure progress, provide opportunity, and ensure accountability for results. Data are presented on 67 city school systems from 37 states and the District of Columbia. The statistics are presented year-by-year and grade-by-grade on each state test in mathematics and reading between 2009-2010 and 2012-2013. City-by-city statistics are available on the Council's website, as well as data by race, language, disability, and income in cases where the states report these publicly. Every effort was made to report achievement data in a way that was consistent with the No Child Left Behind Act--that is, according to the percentages of students above "proficiency." The report also presents important demographic data. Included are enrollment data by race, poverty, English language proficiency, and disability status. Statistics are also presented on student/teacher ratios and average school size. Finally, changes in these demographic variables between 2008-2009 and 2011-2012 (the most recent year on which federally collected data are available) are shown. Data are presented for each city and state. The following is appended: Number of Districts Included in Specific Analyses.