Abstract: A mechanism for the automatic control of a fishing line on a rotating spool fishing reel in order to prevent over runs comprises a clip which can easily be clipped on to and off the reel, two cranks and a yoke. The cranks are pivotally mounted on the clip and are joined to the yoke, the inner ends of the cranks have brake pads in the forms of elastic bands stretched around small tabs which bear against the rim of the spool of the fishing reel in order to brake it if the fishing line is slack. When the fishing line tautens as in a cast it lifts the yoke in turn thereby lifting the brake shoes off the spool rim to allow it to rotate freely during the cast but as soon as the tackle and bait hit the water or for any other reason such as an uneven cast the line slackens allowing the yoke to drop and the brake shoes to come down on the spool rim and brake it to prevent an over run.