G'day Nat,
I don't have any particular bloodline combinations that I like in preference to others so much as I get the almost immediate feeling that some are probably right and will work whilst others are probably wrong and will not. Along those lines I very firmly believe (but have no substantive ideas as to why) there are certain sirelines that will work anywhere, others that will work in here in AUS but not in NZ and vice versa and further still some that will work in the US but not in the Southern Hemisphere and again, vice versa. I wish I knew why but it just is what it is.
I also think there is a fair amount of circumstantial evidence around to suggest that, for reasons that may never be fully explained, some sires do appear to exert an influence in a maternal family for many years beyond that which you'd reasonable expect of them.
Two such horses, IMO, are Able Bye Bye and Scotty Belmont, the latter being a horse I am a particularly big fan of and like to see in a maternal family.
Over the years the number of classy racehorses and successful producing broodmares that have had Scotty Belmont up close on their maternal line is really quite remarkable. The same sort of thing goes for Able Bye Bye. Again, I wish I knew why but it just is what it is.