Sheffield Wednesday and Stevenage sprang the surprises in the FA Cup third round but will we see more shocks in round four?
BBC Sport's football expert Chris Sutton has made predictions for all 16 matches and given his verdict on who will progress.
For this weekend's ties, he is up against Krept, from rap duo Krept & Konan.
Krept & Konan's new single, Dat Way, featuring Abra Cadabra was released on 19 January.
Krept is a Manchester United fan with fond memories of multiple FA Cup wins in the 1990s and he is dreaming of more success under Erik ten Hag in domestic cups this season.