For combinations that happen to end up adjacent to one another in the pie chart. For other combinations, it's not really any more obvious than in the bar chart.

For combinations that happen to end up adjacent to one another in the pie chart. For other combinations, it's not really any more obvious than in the bar chart. Perhaps pie charts would be less sucky if they were interactive and allowed you to rearrange and/or re-colour the slices. Then at least you could go looking for subsets that add up to 50% of the pie (or 31.42%, or 99.94%, or whatever). Though I can't help thinking that there are better ways to do that.