I'm making an obby and I wan't to make stages without using checkpoints. How do I do this?

I'm making an obby and instead of using checkpoints to go from stage to stage I wan't something else. I had previously used checkpoints but lets say I got the stage 10, I would be able to go back to stage 9 and if I died I would respawn at stage 9. I wan't to prevent this from happening by making a leaderboard with stages where if you land on the previous stage it doesn't send you back there if you respawn. Can someone help me?