STOCKHOLM, Sweden — A Finn who helped mediate peace in Indonesia is tipped to win this year’s Nobel Peace Prize, while bookmakers favor a Turkish novelist for the literature award.

But in the hyper-secretive world of the panels that have spent much of the year sifting through hundreds of nominations, it’s all a guessing game until news starts tumbling out today with the announcement of the medicine prize.

Nobel-watchers rely on complex mathematical formulas, statistical calculations, and pure instinct to make their predictions, but they don’t get any hints whatsoever from the awarding institutions in Stockholm and Oslo, Norway.

The prizes established 111 years ago by the Swedish inventor of dynamite, Alfred Nobel, are in the categories of literature, peace, medicine, physics, chemistry, and economics. The latter, many of whose past winners are Americans, is technically not a Nobel but a 1968 creation of Sweden’s central bank.

Winners get a check of $1.37 million, handshakes with Scandinavian royalty, and a banquet on December 10 — the anniversary of Nobel’s death in 1896. All prizes are handed out in Stockholm except for the peace prize, which is presented in Oslo.

Nobel’s instructions were to give the peace prize “to the person who shall have done the most or the best work for fraternity between nations, for the abolition or reduction of standing armies, and for the holding and promotion of peace congresses.”

This year speculation is focused on the August 15, 2005, peace agreement that ended 29 years of fighting between Indonesia’s government and separatist rebels in Aceh province, on the Indonesian island of Sumatra.

Betting agency Centerbet of Australia has the former Finnish president, Martti Ahtisaari, the mediator of that accord, as the favorite, followed by the Indonesian president, Susilo Bambang Yudhoyono, and the rebels’ Free Aceh Movement. A tradition of honoring both sides seeking peace means an Aceh prize would probably be shared.

“Aceh is the worthy avenue down which punters think the Norwegian Nobel Committee will go this year, and, after a slow start, they’re coming for Ahtisaari,” Centerbet’s Gerard Daffy said.

Many bettors correctly picked Mohamed ElBaradei , head of the International Atomic Energy Agency, as last year’s winner. However, the peace prize committee sometimes springs a surprise by picking an outsider, such as Kenyan environmentalist Wangari Maathai in 2004.

While the select group of people and institutions with nominating rights sometimes disclose their nominations, the Nobel committee waits half a century before identifying them.

So Nobel historians only found out this year that President Eisenhower was nominated for the 1955 peace prize, as were the German chancellor, Konrad Adenauer, and the former British prime minister, Clement Attlee.

The committee could not decide so no peace prize was awarded that year.

For this year’s Nobel Prize in literature, Britain’s Ladbrokes betting agency is favoring Turkish novelist Orhan Pamuk ahead of Syrian poet Adonis, Poland’s Ryszard Kapuscinski and Americans Joyce Carol Oates and Philip Roth.

Since three of the last five winners wrote in English, a writer working in another language may have an edge this year.

No date has been set for announcing the literature prize, but it usually happens on Thursday.

The physics prize will be announced tomorrow, chemistry on Wednesday, economics on October 9, and the peace prize on October 13.

The awards sometimes provoke criticism — French author Jean-Paul Sartre turned down the 1964 literature prize, and Vietnam’s Le Duc Tho rejected the 1973 peace prize.

The committees have been accused of a male bias — only 33 female laureates to 725 males.

The committee secretary who will announce the medical prize, Hans Jornvall, cautions against expecting a very recent discovery to win.

“It takes a while for the discoveries to be published,” he said. “It takes a while for the world to take notice, and then it takes a while for the world to nominate.”