Why INEC declared governorship election in 6 states as ‘inconclusive’

INEC chairman, Prof. Mahmood Yakubu, has come under fire for the conduct of the 2019 general elections [Guardian]
The Independent National Electoral Commission (INEC) has declared the result of governorship elections in six states to be inconclusive.
Of all the 29 states where elections were held on Saturday, March 9, the commission has determined after the collation of results that elections are inconclusive in Adamawa, Bauchi, Benue, Kano, Plateau, and Sokoto states.

There’s only one reason why INEC would declare that an election inconclusive and refuse to announce a winner.

According to Section 26 of the INEC Act, the commission cannot declare a winner if the number of cancelled votes can mathematically affect the outcome of the election.

Abba Yusuf of the Peoples Democratic Party (PDP) is in the lead in the Kano governorship election but has to consolidate his position in the supplementary election that’s yet to be scheduled [Daily Nigerian]

So, for instance, if the margin of victory between the first-placed candidate and the second-placed candidate is 100, the number of cancelled votes cannot be any more than 99.
If the number of cancelled votes is 101, or higher, then the election will have to be declared inconclusive since the second-placed candidate can mathematically win the election if all 101 voters cast their votes for just that candidate.

Votes are most commonly cancelled during elections, as with these current ones, when the affected areas witness any form of violence or other factors that compromise the results.

The only way to resolve an inconclusive election is for INEC to conduct supplementary election in the areas where votes were cancelled.

The supplementary elections also have to be conducted within 21 days of the initial polls which is March 9, in this case.

Despite that the contest is usually mathematically between the top two candidates, all the candidates involved in the elections are still allowed to take part in the supplementary elections, and not just the top two as it would happen in a runoff election.

The first and second place battle in the affected six states is exclusively between the All Progressives Congress (APC) and the Peoples Democratic Party (PDP), with the PDP leading in five states and APC in one.

Below is a breakdown of why supplementary elections will take place in the aforementioned six states:

Adamawa State
Umaru Fintiri (PDP) – 367,471

Jibrilla Bindow (APC) – 334,995

Margin – 32,476

Cancelled votes – 40,988

Bauchi State
Bala Mohammed (PDP) – 469,512

Mohammed Abubakar (APC) – 465,453

Margin – 4,059

Cancelled votes – 45,312

Benue State
Samuel Ortom (PDP) – 410,576

Emmanuel Jime (APC) – 329,022

Margin – 81,554

Cancelled votes – 121,019

Kano State
Abba Yusuf (PDP) – 1,014,474

Abdullahi Ganduje (APC) – 987,819

Margin – 26,655

Cancelled votes – 128,572

Plateau State
Simon Lalong (APC) – 583,255

Jerry Useni (PDP) – 538,326

Margin – 44,929

Cancelled votes – 49,377

Sokoto State
Aminu Tambuwal (PDP) – 489,558

Aliyu Ahmed (APC) – 486,145

Margin – 3,413

Cancelled votes – 75,403