In order for the Prepotency Index to be calculated the minimum number of dogs registered was raised to 100. It was felt that this would enhance the validity of the statistic. Small samples can be unduly influenced by careful placement of puppies; this is more difficult with large samples. The increase in the sample size requirement precluded the inclusion of many of the younger dogs in this supplement (that is, the P. I. Is not listed). P. I.s of less than .30 are not reported for two reasons. (1) This document is primarily a ranking of the top producers, and those with a P. I. below .30 may not be considered "top." (2) The P. I. of dogs early in their career as studs have an unnaturally deflated index because some of their offspring take several years to make it into the winning column in all-age and shooting dog competition. For that reason P. I.s end to rise with age. Note the changes in the original P. I. in the 1980 edition in the new figures in the Performance Section of the Supplement. As a point of interest the percentage of offspring winning for dogs with at least 100 pups registered is included. The two rankings are correlated - but not very highly. Possible contributors to the low correlation might be (1) a dog producing a low percentage of winners, but those that do place win more often, and (2) dogs producing a high percentage of winners, but most of them not making the grade to shooting dog or all-age competition. The desideratum, of course, would be one with high rankings on both measures.

Referral to the Introduction of the 1980 edition will shed light on the inclusion of Builders Addition, Fiddler, and Mississippi Rifle. For the reasons stated there they were included in spite of the fact that they did not meet the regular requirements for inclusion. Hawk's Rex has phenomenal statistics, but he didn't qualify, and his sample size is too small to warrant ignoring the qualifications rules. The P. I. On Barshoe Buzzsaw is very high, but collection of data on him didn't start until three years ago which was when he qualified for inclusion. This caused his sample size to be too small to warrant his P. I. His more distant past is now being investigated and percentage of winners will be available to those who are interested at a later time. Flatwood Bill, Flatwood Hank, and The Kodiak are qualified for inclusion, but sufficient data has not been collected for them.

Because of the increase in interest in walking trials a limited number of the top shooting dogs were followed (starting in 1982), and a limited report of the results are included in this supplement. Just as the logical gene pool, according to the law of regression, for shooting dogs are the all-age dogs, the logical gene pool for walking dogs should be the top shooting dogs.

No systematic set of rules was utilized for the stud records of the shooting dogs. This caused Rocky River Buck and perhaps some others to be unjustifiably omitted. He probably, according to the data now being collected, would have been in the top five in the production categories. This type of error will be corrected in the Second Edition.

The 1985 Supplement includes:

The address given in 1980 edition has changed to 134 Pettigrew Rd. NW with the city, state, and zip code remaining the same.