The 19th match will be a tough fight between PSG and Dortmund. Other teams will be playing against relatively strong and relatively weak opponents so the results of other matches are predictable but the result of the match between PSG and Dortmund is difficult to predict. 
Considering the current performances, PSG and Dortmund are two equally strong teams, so their game will be much more exciting. If PSG had Messi Neymar then maybe we would have put PSG ahead in this match but currently PSG don't have these two stars and their best player in Dortmund has left for Real Madrid that's why I put these two teams on equal footing and expect a tough competition between these two teams.