Winning Distance vs DI and CD 2008

The following images graphically display the relationship between winning distance (WD) and DI or CD for North American open stakes winners between 1983 and 2007.  Not surprisingly, there is considerable scatter in the data.  However, the trend lines are clear within the population and show an expected increasing average distance with decreasing average DI or CD.  The correlation coefficient is stronger for the CD, making it the preferred statistical tool.