LOS ANGELES (Hollywood Reporter) - Will the best picture of the year be named best picture at the Oscars on Sunday?

Critics may carp, but members of the Academy of Motion Picture Arts and Sciences could also have reason to gripe that the eventual winner is not in sync with their tastes.

That's because the Academy's complex voting system favors some films over others. And in a race where two titles could easily run neck-and-neck, the voting system can change the results of the election, just as much as it does political ones.

Rick Rosas, a partner at PricewaterhouseCoopers and one of two accountants charged with tabulating the results, says there are years when just a few votes separate the winner from the losers.

"We have had exceedingly close (results), extremely close," he acknowledges. "This is my eighth year, and I definitely recall having to recount a couple of times for best picture."

The Academy uses two very different voting procedures to determine the nominees for best picture and the actual winner. It operates a whole other voting system in the foreign language race.

For best picture, since 1936 the Academy has favored what it calls "preferential" voting, a variant on the well-established Single Transferable Vote system .

The way this works, members (and all Academy members are eligible to nominate best picture contenders) choose five movies that they rank in order of preference. For a movie to get nominated, it must be ranked No. 1 by a fifth of the voters.

But what frequently happens is that only two or three movies cross that threshold. In this case, the Academy takes the movie with the lowest number of No. 1 votes and reallocates those votes to the No. 2 choices on the ballots.

Let's say a voter names " The Day the Earth Stood Still " as his first choice for best picture, but nobody else does. Let's also say he opts for "Slumdog Millionaire" as his second choice. His vote would be transferred from "Earth" to "Slumdog."

The process continues, eliminating from the bottom up, until five pictures have crossed the one-fifth threshold.

When members vote for the winner, however, a different system applies. At that stage it becomes a simple matter of first-past-the-post. So in theory, if four of this year's best picture nominees get just under 20% of the vote, and "Slumdog" gets just over 20%, it will win the Oscar. A plurality, not a majority, wins.

"With five nominees, in a significant number of cases, the Oscar recipient may have less than 50% of the vote -- they never tell us," says the Academy's executive director, Bruce Davis, referring to Pricewaterhouse-Coopers. "Theoretically, in a really tight race, you could win it with 21% of the vote."

Why should we care? The answer is that each system favors a different kind of movie.

For the nomination stage, it doesn't matter if some people are passionate about your movie, even if they constitute almost 20% of the voters; what matters is that enough other people like it so much they are willing to rank it No. 2. So a picture like " The Wrestler ," which has a coterie of ardent fans but which also polarized audiences, might have had a significant number of people who made it their first choice, but not enough second-place votes to end up with a nomination.

By contrast, a widely respected picture like "The Reader" might have been fewer voters' first choice, but it could have ended up with so many second or third-place nods that it was nominated.

This could be one reason " The Dark Knight " failed to get nominated, an oversight that several insiders believe will have a serious effect on the Oscarcast's declining ratings. Many of the Academy's younger members might have made it their first choice, but not enough to cross the 20% threshold. Then too few older members placed it second on their ballots.

If this nominating system favors generally acceptable films over ones that are adored by a passionate minority, by contrast, the method for choosing the winner benefits one film with the most intense support. So if more people are truly passionate about "Benjamin Button" than, say, "Frost/Nixon," it will win the Oscar -- regardless of the fact that "Frost/Nixon" might draw more second-place votes.