Here is one of the best explanations of how wood is sawn.
http://www.hardwooddistributors.org/blog...in-sawn-lumber/
Flat sawn wood sawn over 150 years ago might have been good for stocks because of the how tight the grain was, but not now.
Also back then the wood was air dried and some was left for 25 years before it was used, reasoning was it was subject to hot, cold, wet, dry after all these years and became stable. Now a days they throw it in a kiln for a few days and call it quits, they can't afford to have sitting around.
As you will read, rift sawn is some of the best cuttings but also the most waste.
The best figure is usually from the root or on a large tree, where branches are.

David