A Fish Flingers scorecard is an item obtainable by talking to a Fisherman and asking him to give you one. It used to be obtainable from Fisherman's Wife in front of the Fishing Guild. You can now receive one by talking to the Fisherman and slecting the option "About Fish Flingers..." followed "About the competition score..." and finally the 1st option. It is used to check a player's recent competitions and their best recorded achievements at Fish Flingers Distractions and Diversion.
An example of what you would see when reading a Fish flingers scorecard.