Israeli novelist Amos Oz listens to a question during a meeting with Russian writers in the Russian PEN centre in Moscow, September 7, 2006. REUTERS/Anton Denisov

Israeli writer Amos Oz is favorite to be picked for the 2009 Nobel literature prize next Thursday, but with the judging notoriously hard to predict, he is far from a safe bet.

Oz, who deals with life in modern Israel in his novels, and reflects decades of commitment to the Israeli peace movement in his political writing, is quoted at 4/1 by the British bookmaker Ladbrokes, meaning he has one chance in five of winning.

But Oz was also widely tipped last year, when Frenchman Jean-Marie Gustave Le Clezio won the award.

Joint second favorites are the Algerian novelist Assia Djebar and the American writer Joyce Carol Oates, both at 5/1.

Whoever wins the 10 million Swedish crown ($1.4 million) purse, the decision is likely to enrage as many as it pleases.

Adding spice to attempts to guess this year's winner is debate about whether an American could take home the gold medal that goes with the kudos and cash.

In 2008, Academy member Horace Engdahl caused an outcry in literary circles when he said Americans did not participate in literature's big dialogue. Engdahl was replaced as the Academy's spokesman, though he remains a member of the panel.

Other American writers that are thought to be in the running include Philip Roth, quoted at 7/1, and Thomas Pynchon at 9/1.

You could argue that, based purely on their literary prowess, Oates and Roth should be a shorter price, said Ladbrokes spokesman Nick Weinberg.

But ... Engdahl's criticism of American writing has prompted us to push out their odds.

The last American winner was Toni Morrison in 1993.

The American musical legend Bob Dylan, a perennial on the short list for the poetry of his lyrics, is quoted at 25/1.

MANY POSSIBLES

Adding to the difficulty in guessing a winner is the wide field of possible candidates.

The panel has in the past recognized poets, novelists, dramatists and philosophers. Even a prime minister -- Britain's Winston Churchill -- has won the prize.

Other recipients include the American Ernest Hemingway, the Russian novelist and poet Boris Pasternak and the Colombian magical realist novelist Gabriel Garcia Marquez.

But critics also point to startling omissions, such as France's Marcel Proust or Ireland's James Joyce.

The Academy is tight-lipped about how it chooses winners, other than saying they must be nominated by the great and good of the literary world and that they must be living.

The will of Alfred Nobel, the dynamite millionaire who endowed the awards, says they should go to those who have conferred the greatest benefit on mankind.

In a book on the prize, current Academy member Kjell Espmark says authors are often rewarded for their ability to cast light on their own culture or for dealing with universal human themes.

What distinguishes the great writer from the average, though, has divided critics through the ages. The impact of literature on daily life is rarely as clear as it is in the sciences or economics, where the prizes rarely divide opinion so starkly.

The most interesting thing about most literary prizes ... is often not the act of judgment itself and deciding who is the best -- it's the debates that they precipitate, said David Johnson, coordinator of an English course that studies the Nobel Prize run by Britain's Open University.

When there is debate, it shows up the fault lines of the literary and political culture.