Where and why did the dispute start?

The problems began when Zaka Ashraf was 'elected' as chairman of the PCB for a four-year term in May. The election was held under a new constitution in which the role of the patron of the board, the President of Pakistan, had been changed. Where before the patron simply appointed a chairman for however long a term he chose, under the new constitution, a different process was put in place. The patron would recommend two candidates for the post, who would then be interviewed by a nomination committee (on which two of the four members were appointed by the patron). The nomination would then be approved by a restructured board of governors (BoG), ostensibly the body that steers the PCB, comprised of five representatives from regional associations and five from departments (such as PIA or HBL).

The problem with Ashraf's election was at two levels. One, it was done secretively and in a hurry, ahead of the country's general elections in which the party Ashraf derived his power from - the Pakistan People's Party (PPP) - was eventually voted out. The second was the problem with the composition of the BoG. There was no representation on it of the entire province of Punjab, Pakistan's most populous and arguably its most dominant in terms of cricket players. And two associations, Larkana and Dera Murad Jamali, were newly created and did not even have first-class teams; created, the implication being, purely for the purpose of voting in Ashraf.

On a petition filed by a former cricket official from Rawalpindi, the Islamabad High Court (IHC) found the process to be "polluted" and "dubious." The IHC suspended Ashraf as chairman.

The court asked the PCB to name an interim chairman. It named Najam Sethi - why did the court overrule Sethi?
Once the IHC had suspended Ashraf on May 28, the PCB appealed against the decision, arguing that Ashraf be reinstated so that he could attend an ICC AGM at the end of the month. On June 13 the court upheld the suspension and instead directed a government ministry to appoint a chairman for the board, who could attend the meeting. The ministry of Inter-Provincial Coordination (IPC) was given the task; the ministry sprung up after an amendment to the country's constitution devolved greater powers to provinces. A number of federal ministries, such as that of sports, were dissolved, and now came under control of the IPC.

On June 19, the IPC provided three names to the IHC; Majid Khan, the former opener, captain and board CEO; commentator and one-time board director Chisty Mujahid; and Mumtaz Haider Rizvi, a former chief of the Federal Board of Revenue. On June 24, however, the Prime Minister Nawaz Sharif went outside the list and appointed Najam Sethi as interim chairman.

In a detailed order of its final ruling, released on July 20 (but effective from July 4), however, and irked by the appointment of a person from outside the shortlist, the IHC changed the status of Sethi from acting chairman to caretaker chairman. It reversed his major decisions (including the appointment of Moin Khan as chief selector), allowed him only to oversee day-by-day decisions and ordered elections for chairman to be held by October 18. It even provided a mechanism for the elections, ordering that a chairman should be voted upon by the board's general body, which is made up of regional and district associations, as well as departments (an electoral college of 111 in all). On July 24 the PCB decided to file an appeal - called an intra-court appeal in this case as it is in the same court - against the order, which is being heard by a two-judge division bench.

Why did the PCB, via the Patron's order, appoint Sethi as head of the Interim Management Committee?
The IMC was created on October 14 because it had become clear that the PCB would be unable to hold elections by the given date and they feared what would happen, administratively, after that date. They needed an instrument by which they could at least buy themselves more time to run cricket affairs. It is essentially an ad-hoc committee by another name and was appointed by the Prime Minister. This is another big change in the board, that the patron is no longer the president of the country but the prime minister. This was essentially the result of the IHC's July 20 court order, which said that in line with the devolution of powers of the president, it is no longer appropriate for the post to have any say over cricket and so, it should be up to the prime minister instead (arguably the prime minister had taken control of such decisions anyway because he appointed Sethi before the order). Because Sethi was his original appointment, there was no chance the prime minister was going to have a different person as head of the IMC (which is a newer, fancier name for an ad-hoc committee).

Who is, de jure, the head of the PCB, the chairman or the patron? How does that work?
The head of the PCB for all practical purposes, until the first week of December and the next hearing of their appeal, is Sethi. Though he was suspended by Justice Shaukat Aziz Siddiqui on October 29 for not complying with his election order, as a result of an appeal the board had filed against the July 20 order in the same court, the suspension was effectively overturned for now.