Determines if data points that have the same X value are drawn side by side, or are drawn using the same X value. If Auto ...

Determines if data points that have the same X value are drawn side by side, or are drawn using the same X value.  If Auto then the chart type automatically determines if this is true or false.  Note that setting this attribute to true only has an effect if two or more series in a chart area have DrawSideBySide set to true.