The beginning of instructions to wire a Ethernet jack start with:
Using a wire stripper and wire cutter, strip and trim back the jacket from the twisted-pair wire, leaving about two inches of wire exposed. Untwist the wires only so far as necessary so each wire can be inserted in the color-coded slot in the jack. The untwisted wire should be no longer than a half inch.
Why are twists so important when wiring connectors and jacks?