This invention is embodied by a controlled, variable tension line, payout reel machine. A system of sensors detect line tension and line distance paid out, location, and transmit through wired and unwired communication to a microprocessor. The microprocessor is co-located with the reel structure, which in turn applies, via a brake feature, resistance to the reel which is paying out the line being pulled by the user. This invention pertains to all applications where it is desirable to control the tension in a line paid out from a reel or reel. As stated, the payout motive force is supplied by the person, animal or apparatus attached to the end of the line, opposite the reel. The invention applies to the field of precise and measured control of line tension for sport, sport training, performance testing.