One thing is sure - the new pope will never truly know who voted for him.

Cardinals used to sign their names to ballots, but stopped doing so "due to an old history of intrigues and tensions, when people used to fear the most serious reprisals for their choices," says Michael Bruter, who teaches political science at the London School of Economics.

Even so, factions of cardinals will have made their views known during informal talks between votes.

Romain Lachat, a political scientist at Pompeu Fabra University in Barcelona, says the formation of coalitions - where voting cardinals slowly rally around a man who may only be their second or third choice - is inevitable.

There is no formal process of elimination and cardinals can even vote for themselves - which may explain why conclaves often need more than one round of balloting to produce a pope.