How to Read
One round is 100% like a pie chart. Percentages are represented by the clock hand. Imagine a clock except each minute is replaced by 1%. Essentially, it is something like a pie chart in another pie chart similar to a bar in the bar chart in effect.
The chart in the images I have used for this blog post has been created in Tableau. It is an entry for #DiversityinData. The chart is obviously not a default choice in Tableau and workarounds have to be done. If I could control the thickness of the lines, I would have made them thicker. I would suppose that if the chart is done through more complex means like using Calculated Fields with the "Line Chart" function, it would be easier to manipulate in terms of the thickness and colours of the lines. However, I have done the one in this blog post using pie charts and map layers with the help of Excel to keep the method of creation easily comprehensible for non-mathematical savvy persons like me. Perhaps, a blog post on how to create it in Tableau another time.
The Good
1. An easy-to-read chart for comparison of percentages at a glance.
2. It is easy enough to see where the quarters and halfway marks are.
The Bad
1. Like a pie chart, it is difficult to determine at what angles are the exact percentage marks at.
2. If there are more than 2 clock hands, it will be difficult to trace the movement of time as it would not be linear if time is used as a variable between the clock hands differentiated by colour.
All in all, I would say this is not exactly a new chart type, but another take on an existing kind. Below is the chart in full effect.
