It's time to predict the ATP Top 10 for 2021. Novak Djokovic, Rafael Nadal and Roger Federer look to continue to fend off the fast-improving younger generation. The aforementioned crop of players--- Alexander Zverev, Daniil Medvedev, Stefanos Tsitsipas and Andrey Rublev--- seek a breakthrough. Dominic Thiem has already ascended into the elite tier, but perhaps he can go higher. All the projections are here, in my top 10 prediction.