Boxing, which is one of the oldest Olympic sports, makes is 25th appearance at this year's Games. All events will be held at the Sydney Exhibition Center, Hall 3. The boxing competition is divided into 12 weight classes that range from light flyweight (48 kg or 106 pounds) to super heavyweight (over 91 kg or 200 1/2 pounds). For the first time, all bouts will consist of four two-minute rounds. For the third consecutive Olympics, matches will be scored via a computer. Judges will be required to press a button when punches land. If three of the five judges press a button within the alloted period of time, a point is awarded to the fighter. This policy was implemented at Barcelona to eliminate the controversial decisions that plagued past Olympic competitions. Competitors that reach the quarterfinals but lose are listed as tied for fifth place. Defeated semifinalists are both awarded bronze medals, a practice first instituted in 1952 at Helsinki.