Line-Breeding Project

Those two pups pictured and Clay's Riley dog are head and shoulders better dogs than the others out of that litter. Both at less than 9 months old were on their way to making a strike dog. I would like to hear someone who has done a LOT of line breeding tell me how they cull. To me it is tempting to just keep the ones that by a year old are really making it happen and get rid of the others but maybe that is too hasty. I know there are a lot of stories of late bloomers becoming outstanding dogs but my experiences have taught me that most jam dogs I have seen the last few years are all early starting, fast maturing dogs and personally I value that alot! I don't want to wait 14-18 months for a dog to start contributing. If by 12 months they are not contributing and showing me they have the drive and want to then they are a cull and are not going to be used in a breeding program for dang sure. Not trying to steer the thread off corse just kinda asking a general question.