I have touched on this idea some time ago, but I don't think I explained my query very well. Those familiar with LaTex/PGFPlots will know that when you plot a line series with PGFPlots, you can have markers (=pointer in TaGraph) or not, or you can use a parameter that causes every n'th point to be shown as a marker(pointer) and other points without a marker(pointer). This is very useful with very non-linear plots, because you can show the shape of the line accurately without overcrowding the chart with too many markers(pointers), using just a few markers(pointers) to distinguish one line from another.
I cannot see such an option in the TAGraph documentation, but it's possible I have just failed to find it. The only way I can see of achieving the PGFPlots effect is to plot a composite line, one TLineSeries with lots of points but no markers, to get the shape right. Then overlay that with another, pointers-only, series to distinguish the line. Could I please request such an option, if it would not be too hard to implement? One way would be to add a parameter to the Series.AddXY routine saying whether a pointer should displayed or not, and let the application use this parameter to achieve the every-nth-pointer effect.