ISDS Border Collie Database

STATISTICS FROM THE STUD BOOKS

2. KEY DOGS

A warning is in place here. The following will involve a considerable amount of genetics and mathematics now and then with some references to scientific literature. Don't let it distract you too much. Just read on to get a feeling for how I arrived at the conclusions and enjoy the figures.

Let us calculate the influence of a dog on its descendants by supposing that every child inherits half of its parent. So if father 23 has six children, than each child 'consists of' 0.5 times 23 and in total father 23 is carried on an equivalent of 6 x 0.5 = 3 times 23. If these children bring forth children again, than each of those will inherit 0.25 times grandfather 23. And so on. We repeat this for every dog and bitch that has ever been bred from, nearly 50000. This will give us the influence of those 50000 dogs on the total population of 250000 dogs. The result is sorted according to year of birth of the 250000 dogs and divided by the number of dogs born in each year. The most influential dogs are plotted in figure 2.

The plotted dogs have been selected according to the following criteria:

• It should have a maximum influence in some year of at least 3%,
• and the influence on the dogs born in 2000 should be at least 1%.
• Or the dog has at least 2% influence in 2000.
• If a dog owes his influence to one of his descendants than it is not considered a key dog.
• Only the influence is considered on pups with at least one registered parent. Otherwise a few 'Registered on Merit' pups would suggest that (recent) dogs exist without the blood of famous (old) dogs.

A comment is in place here. In the early years it was easier for a dog to become a key dog. Much less dogs were registered each year (<200 before 1940 and <800 before 1950) compared to the number of dogs registered each year after 1960 (5700 on average). In view of this, Wiston Cap 31154 surely is unique.

For bitches it is more difficult to become a 'key dog' because of the limited direct offspring they can produce themselves. Only one bitch meets the key criteria. John Kirk's Nell 3514 is even on a prominent third place, despite the fact that she never ran an International. Only 5 other key dogs did not compete in an International, see table 1.

Table 1 shows more statistics on the influence of these key dogs on the pups born during the last five years (1996-2000). A five year period is chosen because that is the average age at which parents produce pups. In other words, in five years a new generation is born on average. The older key dogs are present in a so much diluted way that none or hardly any dog can be found without their blood. A dog cannot be bred back more than max%. And if no dogs exist without its blood (%zero=0) then we can never eliminate its influence.

Figure 2.
Graphical presentation of the influence of key dogs on the pups born in each year.
The vertical scale is logarithmic to get more equal separation between the lines.
The curves were smoothed with a five-year moving average filter.

Adam Telfer's Old-Hemp (9), born in 1894, is put forward by Mrs.Grew as probably the most influential early dog. Unfortunately the StudBooks list none of his children (over 200 according to Mrs.Grew). I added three of his children mentioned in 'Key Dogs' and another one from 'The Blue Riband'. That already nearly promoted Old-Hemp to the key-dog status.

Some of the key bitches mentioned by Sheila Grew have a really small influence.
Sandy Montgomery's Jinty (30571): 0.11% maximum / negligible in 2000.
Harry Huddleston's Maddie's ( maximum / in 2000 ):
  2656: 0.36% / 0.009%
  4337: 0.44% / 0.018%
10992: 0.07% / 0.002%

Apparently counting the number of descendants alone will not reveal all established dogs.

Next: 3. FOUNDERS