Notice anything curious about the league table below? It shows the final standings of the Nigeria Premier League, which finished last week. Kano Pillars became the first club in a decade to win back-to-back titles but look beyond that and ask yourself this: have you ever seen a starker difference between home and away results?

The final 2013 Nigerian league table, showing home wins and away wins highlighted in grey. Photograph: Fifa

Ten of the league's 20 teams went through the whole season unbeaten at home, while no team won more than three away matches in the entire campaign. The runners-up, Enyimba, did not even concede a goal at home, winning 17 and drawing two of their 19 home games while winning just once away. The disparity between Gombe United's home and away form is even more striking: they managed to win 18 and draw one of their 19 home games, scoring an average of more than two goals per game, but away they lost every match, managing a grand total of four goals in 19 games. What is going on?

Enyimba's sweep of home clean sheets is unprecedented but the overall trend of home invincibility and away vulnerability is not new in the NPL, where travelling teams face perilous challenges relating to violent crowds, questionable refereeing and, indeed, travel itself. Arriving just before kick-off after long road trips, often on hazardous surfaces, is far from ideal preparation for players. And they do not always arrive. Last season two matches were postponed when first Sunshine Stars and then Wikki Tourists were robbed on their way to games. Mostly, of course, teams do make it to grounds – and that is when they must contend with fans and referees.

Referees must contend with fans too – for the men in the middle being beaten up is not so much a risk of the job as an inevitability. Wikki Tourists and Kwara United both had results overturned this season after particularly vicious attacks on officials at the grounds, while Enugu Rangers were ordered to play six matches behind closed doors for similar reasons. Those punishments were imposed after referees threatened a boycott and demanded bodyguards, though the officials relented after discussions with the League Management Company (LMC), which was set up last year to bring order to a league where violence, corruption and legal disputes between clubs are obscuring the performances of highly-talented, low-paid players (eight of the 23 Super Eagles that Stephen Keshi took to the summer's Confederations Cup play in the NPL).

Lack of funding constrains the LMC's ability to help referees in one crucial way: officials do not receive salaries from the league, rather they get "indemnities" that are paid before each match by the home team. At least, that is how the arrangement is supposed to work but referees complain that some clubs try to make payment performance-related. It is now common for away teams to seek to ensure balance before a game by offering to cover referees' indemnities too. "Sometimes the quality of refereeing can come down to which team offered the most generous expenses," a club official who did not wish to be named told the Guardian.

Even when referees are determined not to be influenced by payments, they must show even greater fortitude to ignore the demands of certain crowds. And even if they do, that is still no guarantee that the home mob will not get their way. "There was an infamous case several years ago when a referee, Dogo Yabilsu, awarded a penalty to Sharks at Kwara United and fans invaded the pitch," recalls the Nigerian editor of kickoffnigeria.com Colin Udoh. "Yabilsu was a colonel in the army and he took out his service pistol and chased the fans off. But Sharks were still afraid of what would happen if they scored so their player deliberately missed the spotkick."

Dolphins' players were equally intimidated at Kano Pillars a couple of seasons ago – so when the home side were awarded a late penalty several of them pleaded with their goalkeeper, Sunday Rotimi, a former international renowned for his penalty-saving prowess, to dive the wrong way, which he duly did.

Football does not, of course, exist in isolation. The sport is affected by problems that bedevil the country in general. That is true for corruption and funding difficulties, and also when it comes to political strife. Accordingly, north-east Nigeria, where the Boko Haram Islamist jihadist group operates, is an especially daunting away assignment – and not just because of the fear of being caught up in incidents such as the bomb attack that forced the postponement of last season's clash between Kano Pillars and Enyimba.

Supersport, the television company with the NPL screening rights, considers the region too volatile to send cameras to the home matches of sides such as Kano Pillars, El-Kanemi Warriors and Gombe United; and rival clubs claim that one of the reasons that none of those sides lost at home this season is because the absence of footage allows them and referees to get away with particularly outrageous abuses.

Northern clubs retort that their rivals are merely inventing excuses. It is never easy to know who to believe, a fact that the LMC discovered last month when the potential title-decider between Kano Pillars and Enyimba was abandoned following a pitch invasion. Enyimba refused to play on, claiming their players feared for their lives, but Pillars officials protested that their fans had simply been "jubilating" after their team scored a goal and pointed out that the pitch was cleared in under 90 seconds, the threshold at which a points deduction becomes mandatory.

The referees' report suggested officials felt the atmosphere was not safe for play to continue, but Pillars, who had been filming the match themselves, produced footage that appeared to show the referee trying to convince Enyimba players to come back on to the pitch.

Not knowing what to conclude, the LMC ordered the match to be replayed at a neutral venue. Pillars took a giant step to the title by winning 1-0, a "home" victory for which the club rewarded their players with the bonus they normally get for away wins – 40,000 Naira (about £155) – one of just three times all season that the champions earned that bounty.