Paddy Power, Ireland's largest bookmaker, started taking bets on the successor of Pope John Paul II five years before the pontiff's death. British bookmakers such as Pinnacle Sports and William Hill plc also offered such bets, with significantly different odds. Cardinal Ratzinger, the eventual choice of the papal conclave, 2005 as Pope Benedict XVI started out with 12-1 odds, but was a 3-1 favorite at the time of the conclave. Mr. Power, the proprietor of Paddy Power, was evicted from St. Peter's Square by security staff before the start of the 2005 conclave for displaying his betting prices, by what he claims were undercover police officers. Paddy Power alone took over $382,000 in bets on the conclave, making it—according to Mr. Power—"the biggest non-sports betting market of all time". The bookmaker is already offering bets on Benedict XVI's successor—with Cardinal Francis Arinze the 10-1 favorite—although it does not offer bets on the timing of the conclave as "that would be in bad taste".
Gambling on papal conclaves is largely internet based, as most conventional sport books, such as those in Las Vegas, do not accept bets on election outcomes. A handicapper for Bally's and Paris Las Vegas said the casinos refused to accept bets on the election because of "taste" concerns. The practice is illegal in the United States under the Federal Wire Act of 1961. Although Gregory XVI's bull of excommunication has never been rescinded, priests openly gambled on the outcome of the 2005 conclave in the Cathedral Basilica of St. Louis and a spokesperson for the Catholic League stated "we really don't see much of a problem with it".