For title fight , I still think PSV cannot be stopped from winning and no matter how hard Ajax will try to catch them , I still think it will be very hard or impossible. Maybe this winter transfer window can produce some big changes and PSV will sell some players which I doubt it can happen until summer but a lot of big teams are having problems in Premier League , Bundesliga and so on and that's why I won't be surprised to see PSV losing some players.
PSV is surely currently have enough ability and quality to stay at the top, but now we have difference of 6 points which is not enough and things can take changes frequently in coming rounds while we will have challenging time for all top teams Ajax is surely trying to have their best which is looking not easy, but they are also good to keep things at the top level while Feyenoord is surely had chance of jumping at third spot but can't go at the top two spots as they are not consistent.