This article in the Agronomy for Sustainable Development Journal explores some of the existing methods to assess potential grain yield, the size of the gap between average and rainfall-limited potential yield and to suggest pathways for future gains in crop yields in the presence of soil degradation, climate change and seasonal variability of rainfall. They focus mainly on cereal and grain legume crops but recognise that oilseed crops such as canola and mustard play an important role in many rainfed cropping systems. »