Anton Du Beke remains the longest-serving professional dancer, taking part from series 1 to series 18. In the fourth and fifth weeks of series 18, he was a guest judge while regular judge Motsi Mabuse was self-isolating, before taking on the role officially in series 19 due to the absence of Bruno Tonioli. Four professionals have won during their first series on the show: Brendan Cole (Series 1), Darren Bennett (Series 2), Artem Chigvintsev (Series 8) and Aljaž Škorjanec (series 11). Jowita Przystał (series 20) won with her first celebrity partner, having already been a part of the show’s previous series. Four professionals have won during their last series on the show: Camilla Dallerup (Series 6), Flavia Cacace (series 10), Aliona Vilani (series 13) and Joanne Clifton (series 14). Following his departure from the professional cast, Ian Waite made regular appearances on the companion programme It Takes Two until 2020. Waite and Darren Bennett both participated in the professional dance troupe in series 8, and Waite stood in as a temporary dance partner in series 8 due to the unavailability of Brendan Cole. Iveta Lukosiute initially joined the show to partner Johnny Ball in series 10 after his original partner, Aliona Vilani, was injured in training. She then became part of the main cast for series 11. In series 11, having previously been announced to be leaving the show, Vilani subsequently replaced Natalie Lowe, who was injured before the start of the series. The producers of the show announced this on 2 September 2013. Vilani is the only professional to have been eliminated first twice in a row, with Tony Jacklin in series 11 and Gregg Wallace in series 12. Vilani & Oti Mabuse are the only professionals to have won more than one series. Mabuse is the only professional to have won twice in a row. Kevin Clifton has had the most appearances in the final of any professional, with five (2013–16, 2018). He is also the only pro to have reached more than two finals in a row, appearing in four consecutive finals in total. Since series 13, the show has had more professional dancers than celebrities to partner them with. In this and in subsequent series, the following professionals have been without celebrity partners: Series 13: Joanne Clifton Series 14 and 15: Neil Jones and Chloe Hewitt Series 16: Neil Jones, Luba Mushtuk and Johannes Radebe Series