ALTHOUGH your article ( Post, January 4) on Sonya Osugi's remarkable double-ace does not quote the odds of such a feat, it is possible to work them out from the information you give. If the odds on getting one or more holes-in-one in an 18-hole round of golf are 43,000 to one, then assuming all holes are equally difficult and are independent of each other, the odds of two holes-in-one in a given round should be about 3,915,524,353 to one (that is, about four billion to one against). If the average player plays 50 rounds a year for 20 years, then he or she still only has about a four million to one chance of achieving the double. The odds on the triple would be around 568 trillion to one; that is, if every person in the world took the afternoon off and played one round a day every day, we would expect this to happen about once every 311 years. Obviously some players are better and some courses easier than others, given that this has been done twice! DAVID WEBB Pacific Place