How do they narrow the Grand National runners down to 40?

Question

Correct me if i`m wrong. there are 100+ runners listed for the National but only 40 will be allowed to run in the race. how do they narrow they pack down? and are any of the horses guaranteed to run in the race?

Thank you.

Answer 1

polo is correct the top 40 rated in the handicap are guaranteed to run if they want to. the rest are waiting for horses to drop out

Answer 2

If there are too many runners, only the top 40 rated horses will be allowed to participate.....