Same sire/bitch then you should have the same probability of getting the same outcome. However, since there are so many combinations of the genes you will not get the exact % as in the first litter. You'll have to make more repeat breedings to get an average of both parents. If both parents are above then you should have above average dogs. The first litter may be an extreme case of the good combinations, the second breeding may result in the low extreme. However, after enough trials of the same breeding you'll start to see a trend towards an average. For example, if you see kids from the same family of ten kids. All the kids look alike. No two look the same but they all resemble each other. One may be the tallest, one may be the shortest. All the other kids sort of fall in between. With respect to repeat breedings, the second breeding may end up being better then the first. It's all probability. Some breedings with two champions did not yield anything worthy and was not repeated. The breeder did not realize that they could have examples all the worst genes.