In something of a novel turn, only one of this year’s adapted screenplay noms comes from a novel.That film, “Sideways,” has the best pedigree coming into this year’s race, having racked up a hefty collection of blue-ribbon notices from critics groups and awards, and it would surprise no one if it completed the set by taking home Oscar. That co-writers Alexander Payne and Jim Taylor are the only contenders in this category with a previous Oscar nom only shows the Academy relishes their work and may be more inclined to reward them than the newcomers. This also appears to be the category least likely to be affected by the “Sideways” backlash that has been growing in recent weeks among critics who say praise for the October release has been blown out of proportion. The most unusual contender is “Before Sunset,” a script developed by director Richard Linklater, writer Kim Krizan, and stars Ethan Hawke and Julie Delpy in a sequel to 1994’s “Before Sunrise.” Categorized as an adaptation because it’s an extension of the previous film, Hawke and Delpy took a strong hand in developing the characters they reprised from the previous film. While the film seems almost improvised, the dialogue was tightly scripted to take the guesswork out of shooting the film’s real-time Golden Hour — the special lighting of late afternoon — setting in a short timeframe. That works both for and against the film as the ease with which the script is executed may make the craft of writing easy to overlook. The loose source material of F.X. Toole’s boxing short stories required Paul Haggis to create for “Million Dollar Baby” actions that demonstrated simple truths and to flesh out and tie together characters and plots from multiple stories. But the script is most likely going to stand out to Oscar voters for being complete, even after it takes a radical and unexpected turn that could have cut the film into two unequal halves. First-time screenwriter David Magee faced similar tasks in turning Allan Knee’s play “The Man Who Was Peter Pan” into “Finding Neverland,” compressing a decade’s worth of events real and dramatized into a year for the script. Written six years ago, the script shows a literary confidence and gentleness that should appeal to the traditional tastes of Academy members. Finding humanity in a real-life story also was the key to Jose Rivera’s “The Motorcycle Diaries.” Rivera tapped the memoirs of Alberto Grando and Che Guevara but avoided politics to focus on the coming-of-age story. The resulting character arcs give the movie a strong spine and universal truth that could help it transcend language barriers that have traditionally kept Oscar in English-speaking hands. It will have an extremely difficult time, however, trying to prove itself strong enough to break through that barrier against some extremely tough competition. Before Sunset Richard Linklater, Julie Delpy and Ethan Hawke (story by Linklater and Kim Krizan) Based on characters created by Linklater and Krizan Current kudos: WGA (nom) Oscar pedigree: None Why it’ll win: Sparkling, natural dialogue reconnects auds with characters they already know and like in a deceptively simple way. Why it won’t: Film’s easy, improvised feel belies the detail with which it was scripted and could slip under the radar of voters. Finding Neverland David Magee Based on a play by Allan Knee Current kudos: None Oscar pedigree: None Why it’ll win: Carries on a literary tradition that Oscar loves to celebrate in a way that’s smart and gentle without being saccharine. Why it won’t: Six-year-old script and frosh screenwriter’s effort lacks the visceral emotional punch of its competition. Million Dollar Baby Paul Haggis Based on stories by F.X. Toole Current kudos: WGA (nom) Oscar pedigree: None Why it’ll win: Although we’ve seen “Rocky”-like boxing pics before, this one goes beyond that and then delivers the best plot twist since “The Sixth Sense.” Why it won’t: One viewer’s plot twist is another’s cliche and this mix of boxing and tragedy won’t impress everyone. The Motorcycle Diaries Jose Rivera Based on books by Ernesto Guevara and Alberto Granado Current kudos: WGA (nom) Oscar pedigree: None Why it’ll win: Its journey into a little-known part of the world evokes universal truths and emotions that should stick in voters’ minds. Why it won’t: While foreign-lingo scripts have won in the past, this one doesn’t look like it has the chops or mainstream appeal to come out on top. Sideways Alexander Payne and Jim Taylor Based on the novel by Rex Pickett Current kudos: Golden Globe (win), WGA (nom), NBR (win), L.A. Critics (win), N.Y. Critics (win), Boston Critics (win), Chicago Critics (win) Oscar pedigree: “Election” (nom) Why it’ll win: Script has swept up pre-Oscar kudos and is the strongest element in an especially strong and well-reviewed film. Why it won’t: The constant stream of praise has worn out its welcome and could prompt voters to reconsider their support for the film.