Millions of Kenyan voters are waiting for the outcome of Tuesday's closely contested election as opposition supporters protested in pockets of the country.

Hours after provisional results started trickling in, veteran opposition leader Raila Odinga rejected the count and claimed the country's electronic voter system was compromised.

Odinga, a former prime minister of the east African country of 48 million people, also disputed the results of the 2013 election, which was later settled by the court.

Kenya embraced a multi-party democratic system in 1992, and the country has held six presidential elections since. In only one - in 2002 - has the losing side accepted the vote count.

In 2007, the opposition coalition disputed the electoral results after incumbent Mwai Kibaki was declared the winner, sparking ethnic killings that left more than 1,200 people dead and 600,000 displaced from their homes.

So, why are most election results disputed in Kenya?

Lack of transparency

The voting process is often smooth with minimal glitches. The disputes appear as soon as the tallying of votes starts.

"Kenya's electoral body has a record of not being transparent. They leave too much room for suspicion. They are not timely nor credible when it comes to releasing information," Abdullahi Boru, a Nairobi-based analyst and researcher, told Al Jazeera.

"When the process is not transparent, it is easy to claim votes have been stolen," Boru added.

The government invested heavily in a new electronic voting system for this election. But that appears to have done little to increase the opposition's confidence in the electoral process.

Close Elections

Elections in Kenya are fiercely fought, and the winning margins are close. To be declared winner, a presidential candidate must garner at least 50 percent of the votes, plus one.

In 2013, President Uhuru Kenyatta took home 50.07 percent of the votes cast, avoiding a runoff by the slimmest of margins. Odinga took home 43 percent of the votes cast.

Financial stakes

Campaigning in Kenya is expensive with party donors spending a lot of money to get their favourite candidate into the presidential palace.

Presidential hopefuls also spend a fortune from their own pockets to stand a chance.

Candidates are under a lot of pressure to come out on top at the end of the vote count.

"The stakes are too high. They have borrowed heavily to finance their campaigns. Campaign donors will have given them a lot of money too. Candidates feel they can't lose," Boru said.

The flow of large amounts of money into the political system of this young democracy is alarming analysts.

"Laws to regulate funding to election campaigns needs to be put in place. This way the stakes will be lowered," Njoki Ngumi, a political analyst, told Al Jazeera.

Incumbent dilemma

No incumbent president has ever lost an election in Kenya. A president is elected for a five-year term and can only serve two terms.

Opposition candidates have on many occasions accused the ruling party of using state resources to carry out their campaigns.

"No sitting president will want to go down in history as a one-term president. Losing is not an option to many of them," Boru said.

Candidate age

When Kenneth Matiba, who came second in the 1992 presidential election, ran for office, he was 70. Kibaki was 75 when he ran for a second term in office in 2007. And Odinga, who is the opposition flagbearer, is 72.

"These candidates feel they may never get another chance to lead the country. They tend to be in their 70s and not in the best of health," Boru said.

Coalition government

Following the disputed 2007 elections, Kibaki and Odinga formed a coalition government.

Kenyatta, while addressing a campaign rally last week, denied attempts to rig the elections and said the allegations by opposition leaders were a ploy to form a coalition government.