Ron Guth:
The earliest Dimes of 1873 were of the same type as in previous years, without the arrowheads that appeared on either side of the date later in the year. There was a problem, though, with the first Dimes of the year. The 3 of the date looked too much like an 8 because the ends of the loops were too close together. This was corrected early in the year, resulting in the Close 3 and the Open 3 varieties.
The mintage of the Close 3 variety is over 1.5 million pieces compared to a mere 60,000 for the Open 3 variety. Though the population of PCGS-certified examples of both varieties is nearly equal, the quality of the Close 3s is higher overall. At the top end, the best example is a single NGC MS67 from the Gene Gardner Collection (recently sold for $6,462.50). MS63 is the most frequently seen grade.