The splinter someone finds with their tongue was decided months earlier, in a factory, by three process choices.
Grain direction
Bamboo split along straight grain breaks clean; twisted grain tears.
Good manufacturers select for it; cheap ones ship what arrives.
Moisture at the split
Kiln drying to the right level makes the break crisp; too wet tears fibres, too dry crumbles them.
The pull’s feel is largely a moisture spec.
The milled bridge
The join between the pair is machined to direct the break.
A properly milled bridge fails exactly on the line — every pair, every case.
The buyer’s test
Pull twenty pairs from a sample case: count crooked splits and run a finger down every edge.
A supplier confident at the case level will invite the test.