Radwanska leads their previous matches 6-5. They last met in October last year with Radwanska taking that in straight sets on a hard court. They met once indoors which was in Oct 2013 and Kerber won in 2. Only 1 of their last 7 matches went to 3 sets.
World number 1 against the defending champion. This could be a great match. Kerber has won all her round robin matches dropping just 1 set to Cibulkova. She has had to work hard at times for her service holds and Keys put her under a decent amount of pressure in her third match.

Radwanska lost to Kuznetsova having had match points. her next 2 matches were won in straight sets but they were not easy victories. Muguruza was able to break her 4 times and Pliskova was ahead in both their sets.
This has been Kerber’s year by a huge margin. Two grand slam titles and a third slam final. Surely she will give everything to win the year end finals. I think we have a slight chance of 3 sets.
Back Kerber if she is broken