which sport is the hardest to make it professionally?

Tennis, golf or boxing. These have the fewest people that actually get paid to play. I.E. professionals.

Football has around 1700 players each year.
Basketball has around 360 per year.
Hockey has around 700.
Baseball around 1200.
Please do not say soccer. There are a million leagues world wide and therefore makes no sense due to the fact that there are thousands of professional soccer players.

The hardest position to play in any sport is quarterback. No question. There are 32 of them each year and most of them still suck. Only around 10 decent quarterbacks on the entire planet. Doesn't get any tougher than that.

MMA an WWE an boxing

WNBA. There aren't that many teams. I think there's only 3 rounds in the draft. There's only 12 teams.

If you mean a career, the NFL. Most player a last about 2 years and then they're out of theNFL.

I would say the NBA. Millions of people are working their hardest everyday to be the best they can be. But each year only 60 of the thousands in college and overseas get picked