Phil over at the Gelman blog wondered how to improve this bewildering (but pretty) data display. Data-rich it certainly is. The table collects together the returns of 12 categories of funds over a 15-year period. The fund returns are specified, as are the ranking of each fund within the dozen for each year.
If the purpose is to confuse customers, i.e. to claim that fund class does not matter, then this chart succeeds. However, on closer look, one might observe that three of the 12 classes showed up disproportionately at the top rank so the chart is somewhat misleading. Directional evidence is buried in the palette of colors; but how to separate the noise from the signal?
As usual, there is no single "best" graphic. The "best" graphic is one where form matches function. If my goal is to help customers understand their expected return and risk for different fund classes over the last 15 years, then the side-by-side boxplot works wonders.
CPI and T-bill stands out as relatively low median returns but exceedingly low dispersion of returns. International was off the charts in terms of fluctuations and also had the third-lowest median return during this period. etc. etc.
If ranks were more of a concern than returns, the same chart can be reproduced using ranks on the vertical axis.