Question Weight Training In Sports

hey guys
i’m doing a research project on the effects of weight training on sports in general . should all sports weight train?
including golf or tennis? can an elite athlete be too bulky for sports other than football or wrestling

A few thoughts:
Im no expert, but a golfer should lift. The rotation and pivot involved in a golf swing would be greatly aided by a solid “core”. I hate to use this word because it has been thrown around so much. Not to mention that golfers develop tremendous over use injuries because they always golf from their favored side. I wont go too into detail because golf is not my thing.
As far as tennis, foot work is paramount. So if their movement foundation is weak, so is their foot work. But this doesnt mean they have to be demi-gods, it’s up to the coach to decide what is the strength goal.
All athletes should do at least some weight training. If all skills are equal, the more physically prepared athlete will prevail.
I once heard the 'two-inch theory" some where which goes like this: If you can jump two inches higher, run two inches farther, push two more inches, you will win. Hope this overkill helps,