Yahoo's popular vote total still shows 51% to 48%. They are truncating, not rounding. It's actually 51.52 to 48.48. I'd round that to 52-48. Given that the difference is 3%, 51-48 seems quite reasonable. Assuming a perfect two-way split, I'd think the following would be the best roundings:
| Winner's share |
Report |
| below 50.25 |
50-50 |
| 50.25-50.75 |
50-49 |
| 50.75-51.25 |
51-49 |
| 51.25-51.75 |
51-48 |
| 51.75-52.25 |
52-48 |
I don't know if anyplace formalizes this procedure, but it's based on much the same principle as the 'rounding' algorithm used for PostScript® rendering: symmetrical rounding would halve the effective resolution for stroke widths. Assymetric rounding results in a slight loss of positional accuracy, but enhances stroke-width accuracy which is often more 'important'. Likewise when showing winning/losing percentages, what really matters is the difference. Using straight rounding for both would result in the differences always being even numbers. Using assymetric rounding means the difference will be accurate to the nearest unit.