Ron Guth: The first Three-Cent Nickels of 1873 utilized the same-sized date logotypes as in previous years. Unfortunately, the small date and the shape of the 3 made it appear to be an 8 at a quick glance. Mint officials noticed this discrepancy and changed the shape of the 3 by opening the loops so that it no longer looked like an 8. By doing so, they created two varieties for the year.
According to the PCGS Population Report, the certified population of the Closed 3 variety is almost twice that of the Open 3, which is in line with their original mintages. Despite this difference, most price guides value them equally.
The finest examples certified by PCGS include ten MS66's.