The Olympic program is constantly changing and evolving (sorry about your withdrawal in 1900, Basque pelota), but there haven’t been many Olympiads that have seen as many changes as the one between Rio 2016 and Tokyo 2020.
The Rio de Janeiro 2016 Games saw 28 sports with 306 medal events, but this will increase to 33 sports and 339 events for Tokyo 2021. With new events in skateboarding, surfing and karate, as well as the return of baseball and softball, there will be more events than ever before. But there will also be fewer competitors in total: 11,238 athletes took part in Rio five years ago, while only 11,091 are expected so far in Japan.
Wrestling was originally to be removed from these Games, but was fired by the IOC in September 2013.
New events for Tokyo 2020
Archery (1): Mixed team event
Athletics (1): Mixed Relay 4×400
Baseball (1): (men only)
Basketball (2): 3 against 3, Men and Women
Swimming (3): 800m freestyle men, 1500m freestyle women, mixed 4 × 100m medley relay
Cycling (4): The Madison (Men and Women), BMX Freestyle (Men and Women)
Fencing (2): men’s team saber, women’s team foil
Judo (1): Mixed team event
Karate (8): (Kumite, three weight categories for men and women; Kata, men and women).
Skateboard (4): (Park Men and Women, Street Men and Women)
Softball (1): Women
Sport Climbing (2): Men and Women
Surfing (2): Men and Women
Table tennis (1): mixed doubles
Triathlon (1): Mixed team relay
Events removed from Rio 2016
Weightlifting (1): Modified weight limits, one less men’s class