as far as I can see, Newcastle has more consistent, more stable performance. Newcastle defensive line is still stronger than Chelsea and in terms of attack, both have almost the same performance and I would probably choose to bet on the double chance.
Of course Newcastle United has been really performing very well this season and comparing there performance with Chelsea I believe they are equal but however Newcastle United has made more wins than Chelsea because Newcastle United seems to have some good records this season but however the only league they seem to have been struggling is champions League because there group is one the toughest group and qualifying from that group is a big challenge for them, so that's why they are at the button of there group table.
So perhaps since Newcastle United knows that they stands no chance of going far on champions League they really make sure they never go the same way they did on the champions League, so they will never allow Chelsea to win them, perhaps with home advantage they have a very high chance of winning the match.