Have you been to the venue before and checked out the lighting? If it’s got enough lighting from different angles it’d help you to get better and cleaner shots! If you don’t feel the lightings are enough perhaps tell the organizer to see if they could set up more lights.

On the lens 50-300 it’d be too tight if you’re at the ring side. If you are at the ringside you could borrow/rent out a 24-70 lens and you’ll be able to get some good close tight shots and a slightly wider shots.

If you can only bring 50-300 then obviously you’d need to locate yourself a bit further away from the ring and make sure theres no object blocking your views when you take the shots. Enjoy it!

Thank you for sharing! I’ve taken photos for a few boxing matches as an amateur and I too enjoyed reading this!