The contest in Squid Game consists of six games, and initially there are 456 contestants.
- We know that, after the first two games and the nocturnal brawl, there are exactly 80 players remaining. They form eight teams of ten players each for the third game.
- The third game, by design, eliminates exactly half of the players. Again we see on the big display board that there are exactly 40 players remaining.
- After the third game, the doctor (player 111) gets killed. That should leave 39 players.
- The remaining players form pairs for the fourth game. The manipulative woman (player 212) correctly notes that there are an odd number of players remaining after the doctor was killed, and she ends up being the odd one out, unable to participate in the fourth game.
- Presumably, then, there are 19 pairs for the fourth game, which again is designed to eliminate exactly half of the players. Since player 212 survived by default, there should be 20 players left after the fourth game.
But when everyone comes back into the sleeping room at the start of episode 7, the big display board says there are 17 players remaining. (This is reduced to 16 before the fifth game by player 069 committing suicide.) What am I missing? Did some matches in the fourth game result in both players getting eliminated? Did someone else get killed that I've forgotten about?