Forecasting the uptake of competing products is complex and requires substantial Excel skills. The previously covered Bass model is great for forecasting individual product uptake, but what about when you need to forecast the uptake of your product amongst competition? It isn’t as simple as forecasting the uptake of each competitor individually – you need to forecast how competing products interact. In this paper, we look at Frank Bass’s Law of Capture and how it can be enhanced when forecasting pharmaceuticals.