I am definitely predicting a first round victory for John Mahama, and also but with less confidence predicting he will get over 50% and there will not be a second round.
The regional swings look like this with 91 constituencies in my calculations:
Ashanti Region 1.9% swing to NDC
Brong Ahafo 3.9% swing to NDC
Central Region 1.9% swing to NDC
Eastern Region 0.5% swing to NDC
Greater Accra 1.4% swing to NPP
Northern not enough results
Upper East not enough results
Upper West 21.4% swing to NDC
Volta 3.2% swing to NDC
Western 2.9% swing to NDC
John Mahama needs an overall swing of 1.5% compared to the 2008 first round to overtake Nana Addo, and needs an overall swing of approximately 2.4% to get over the 50% margin and win in one round. That is an estimate based on the poorer performance of minor parties.
It looks like he will do it, but this is a projection based on a third of the results (not all of which were useful due to complex boundary changes). It is a fact that the majority of the first dozen or so results declared gave a definite swing to Nana Akuffo Addo and the NPP, across a variety of constituency types and regions, causing me and other pundits to jump to quite wrong conclusions. It cannot be ruled out that there will come a long run of swings to the NPP, but it is looking statistically unlikely now.
The swing is pretty consistent and there are not obvious anomalous results. The massive swing to Mahama in Upper West is in part a reflection of the expected northern excitement at having a northern president, and was predicted. I expect we will see larger than average swings to Mahama in Upper East and Northern as well.