Specimen Fishing Tips | How to single out bigger rudd - Kevin Sanders
First of all, you need to fish at peak feeding times, namely dusk and dawn. Big rudd might feed during the day, but it can be hard work if it’s hot and sunny.
Second, use polarised glasses to find the bigger fish before starting. If you can’t see them, try feeding chunks of bread and see if any rudd start taking off the surface.
Finally, don’t just cast and hope for the best. If you can see a larger fish feeding, target it by casting your bait just upstream or upwind, and let it drift to the target. Being greedy, big rudd will often beat the smaller fish to the hookbait.