I think it is only boxing that does this but not sure. I only learned boxing did it a few days ago when a Canadian fighter won his quarterfinal match and the announcer said "and that will guarantee him a medal". At first I thought he had gotten overzealous and made a mistake but later in the broadcast they explained how it worked. 

grayruby

I hate that. Do any of the tournament style competitions have bronze medal games?

I thought there was a different method of assigning 3rd place in competitions like that.

Undisciplined

Stacker_Sports

Stacker Sports- Saturday Poll

“The rule was introduced due to the short interval between the semi-final and the third-place match. The boxers did not get adequate time to recover, which risked their health.”