Yeah, but here's the thing: sometimes the best performer isn't the best producer
For example, Ch Stormbringer was the best dog in the litter, but his brother Crews' Sandy (Warlock) was the best producer.
Another example, Ch Vengence was the best dog in his litter, but his sister was an ace too, and his brother Techno was the better producer (Vengence was sterile).
Another example, Jezebel was the best dog in her litter, but Duke Nukem, Laguna Sunrise, Mystery, and Athena Red were all extremely game, conformationaly-flawless dogs who produced winners and DG animals.
Bottom line is, in a legitimately good litter, there will be A LOT of good dogs, not just "one" ... so if you think only "one" dog in the litter is going to be good, then I wouldn't get any dog from that litter.
And if it's a damned good breeding, then you should be happy with any of them, because there will be MANY valuable dogs produced, not just one
Jack