What is the meaning of OMP, GWP, OGP?
These are percentages, used by the DCI as tie-breakers. From Section C4 of the Tournament Organizer's Handbook:


OMP - Opponents’ Match-Win Percentage. A player’s match-win percentage is that player’s accumulated match points divided by X
times the number of rounds in which he or she competed, or 0.33, whichever is greater.
GWP - Game-Win Percentage. Similar to the match-win percentage, a player’s game-win percentage is the total number of
game points he or she earned divided by X times the number of games played.
OGP - Opponents’ Game-Win Percentage. Similar to opponents’ match-win percentage, a player’s opponents’ game-win percentage is
simply the average game-win percentage of all of that player’s opponents. And, as with opponents’ match-win percentage, each opponent has a minimum game-win percentage of
0.33.