Several new runner market type peanut cultivars have been released in the past 5 to 7 years. In 2005, a “Seed Index” was developed by industries that purchase and utilize runner type peanuts. The purpose of the index is to create standard acceptance criteria for several broadly important components of peanuts and use the criteria to screen peanuts prior to entering the market. Seed size is an important characteristic in the Seed Index and one target is 50% medium kernels. Medium kernels are defined as those that do not fall through a screen with one-half inch by 18/64 inch slots. None of the commercial cultivars tested in 2002, 2003, and 2004 in Marianna, Florida had 50% medium kernels. In 2004, only 9% of 1022 genotypes (experimental lines and commercial cultivars) tested had 50.1-55% medium kernels. In contrast, 68% of the 1022 genotypes had 35.1-55% medium kernels. These results suggest that the 50% medium kernel criterion may be too restrictive resulting in a significant bottleneck in developing new cultivars. We suggest that the criterion be adjusted to a minimum of 35%.