32 (40- see below) players simple bracket style tournament.
ATP style means that first round games and the brackets will be organized according to players ranking at the time of the games organization, i.e., highest score player against lowest, second highest score against second lowest, and so on; this method will continue into the advanced rounds of the tournament - quarter finals, semi finals and the finals.
Also, first 24 Players by their score will qualify to round 1 automatically; The other 16 players will play one qualification round, knockout, and the 8 winners of the qulification round will join the other 24 players for a standard bracket 32 players tournament, sorted in round 1 by their score as explained.
General Echeivement Medal - A GA medal for the Best Underdog Killer will be granted - the player with the lowest score who kills the player with the highest score. The medal aheivement will be determined by the delta of the scores of both players at the time the round games are being set (for example: if at the time the round games are being set, player one a score of 1400 and the other player two has a score of 1800, and the lowest player wins, than his underdog killer ahcievement is 400, and if no one makes a better one by the end of the tournament, he'll be the medal winner).
This is the third tournament, not the second, make sure to update the tournament's first post with any new and additional information. And you need to make sure to get the GA Medal approved before posting it.
Also, please to start your tournaments in a more timely manner, so you don't have double the sign ups required.