Question 1119412
start with 4 teams, 2^3.
A plays B
C plays D
E plays F
G plays H
The second round features 4 teams, 2 matches
The third round features 2 teams and 1 match for the championship.  
That is 7  matches or 2^3-1
1024 is 2^10
The number of matches is 2^10-1 or 1023.