Good post, which pretty much sums it up: inbreeding is merely genetic magnification.

And, in using this magnification tool we call "inbreeding," you will increase whatever traits you have noticeably. The trouble with using this tool is oftentimes this means you magnify the bad traits! For example, using slightly cow-hocked (related) parents, who are still competitive, might produce an absolutely bowl-legged undershot offspring that can't whip a puppy. Or, in another example, using slightly short-winded parents inbred together might produce an offspring that can't run around its chain spot without getting heat stroke. Therefore, since most people use dogs that aren't really very good to begin with, when they inbreed on them that get "all crap" ... and so they blame "the inbreeding" rather than their poor selection of "which dogs" to plug-into the formula!

Because, so too can you inbreed one super-athletic, structurally-wonderful dog back to its equally-wonderful, athletically-exceptional relative and get just a fantastic litter of all-wonderful, fast, super-athletic animals ... IF you plug the right dogs into the inbreeding equation

It all boils down to SELECTION.

Jack

PS: If you make a super-tight inbreeding off of two excellent dogs, and some of them come out lousy, while most of them come out excellent ... the excellent dogs have essentially been "purified" of the bad traits and are what you carry your line forward with.