Facts about the voting process

The 117th session of the International Olympic Committee (IOC) will vote Wednesday on whether London, Paris, New York, Madrid or Moscow will host the 2012 Olympic Games. Video presentations by the rival cities will precede the voting.
Ninety-nine of the 115 eligible IOC delegates are expected to vote in the first round, with those from the candidate cities and Rogge excluded.
If a city does not secure a majority, the candidate with the least number of votes is eliminated.
The eliminated city's IOC delegates are then allowed to vote in the next round and the process is repeated until a city secures a simple majority.
IOC members will vote secretly by electronic device, which immediately and securely tallies the votes.