Based on the results we've received so far, some key points to be made:

• NA-131 Lahore, previously won by PTI (Imran Khan) seems primed to go over to the PML-N (Saad Rafique). This isn't particularly surprising, given Imran Khan's margin of victory on that seat in the July 25 election was a wafer-thin 0.36pc. Saad Rafique had barely lost that election.
  
  
• NA-35 Bannu, previously won by PTI (also by Imran Khan), now seems primed to go to the MMA (Zahid Akram Durrani). This is, again, not surprising considering that the PTI chairman himself had managed to win with a margin of only 2.84pc in the July 25 election. Zahid Akram Durrani's father, Akram Khan Durrani, had been the runner up in that contest, getting over 106,000 votes.
  
  
• In NA-124 Lahore, Shahid Khaqan Abbasi of the PML-N has handed a thumping defeat to PTI's Ghulam Mohiuddin Dewan. Again, this is not surprising, since this seat was vacated by another PML-N supremo, Hamza Shehbaz Sharif. Hamza had won this seat by a thumping margin of 25.24pc in the July 25 general election, signalling that the PML-N enjoys heavy support in this constituency.
  
  
• NA-60 Rawalpindi is proving to be a real nail-biter. The PTI candidate, Shaikh Rashid Shafiq, is ahead by only a hundred or so votes against his rival, the PML-N's Sajjad Khan. This is a surprising result, given that NA-60 is Shaikh Rashid Shafiq's uncle's home ground. His uncle is none other than the Awami Muslim League's Shaikh Rashid. This was expected to be an easy fight for the PTI, but it seems it will go down to the wire. One reason for the tight race might be the local PTI leadership's unhappiness with Shafiq's nomination for the seat.
  
  
• Similarly, NA-56 Attock, where the PTI's Tahir Sadiq had won by a comfortable margin of 16pc of total votes cast in that constituency on July 25, has swung strongly to the PML-N this time. The PML-N's contender in both contests, Malik Sohail, clearly enjoys strong local backing, having received 99,404 (July 25) and 103,257 votes (October 14) in the two contests. He also seems to have successfully mobilised his voters compared to the PTI, as is evident from a higher vote count than the general election. This is a surprising feat, considering turnout is generally much lower in by-polls.
  
  
• NA-69 Gujrat will, as expected, go to the PML-Q's Moonis Elahi. Moonis's father, Chaudhry Pervez Elahi, had swept the July 25 election for this seat with a comfortable 33.5pc margin of victory. The seat is a stronghold for the PML-Q, and it was expected that it would be retained.
  
  
• Likewise, NA-243 Karachi and NA-53 Islamabad have returned, as was expected, to the PTI. The PTI had won these constituencies with margins of 41pc and 27.5pc of total votes cast in the July 25 election, respectively. It clearly has a strong vote bank in these areas.
  
  
• NA-63 Rawalpindi and NA-65 Chakwal have been comfortably retained by the PTI and PML-Q, respectively. Both were expected to be tough fights, but the PTI seems to have mobilised a healthy number of workers in Rawalpindi, and the PML-Q seems to have benefited from the PML-N's withdrawal of its candidate from the Chakwal seat.

The last word: Although the voter turnout was understandably lower than the general election (it usually is the case in by-polls), the PTI has experienced a much larger decline in voter turnout than its rival parties in some key constituencies.

This could be due to various factors, including but not limited to: a drop in PTI supporters' enthusiasm level; a lack of voter mobilisation by PTI candidates; a renewed wave of support for the opposition; some voters switching parties; and so on.

At this stage and without additional information, it is impossible to pin the reason down to any one factor; however, it is clear that the PTI has reasons to worry.

All analysis is based on unofficial, preliminary results. Please note that the count is still ongoing and final results may be different.