The rules
Simple to learn, hard to survive. Here's exactly how a Last Player Standing competition plays out.
Every gameweek (with 8 or more fixtures to choose from) you select one team you believe will win. If your team wins, you're through to the next round. If they lose or draw, you're eliminated.
You can only use each team once. Once you've picked a side, they're off the table for the rest of the competition.
If you've used all available teams, every team becomes selectable again for the players still standing.
Don't pick by the deadline? That's down to your organiser's chosen rule: either you're automatically assigned the first available team (alphabetically) that you haven't used yet (the default), or you're eliminated. The rule is set when the competition is created, so check yours.
There is always ONE winner. If every remaining player is eliminated in the same round, they all come back in and pick again.
If a fixture is cancelled or postponed after you picked a team in it, you go through to the next round automatically (and the team still counts as used). Once a fixture is flagged as postponed, it can no longer be picked by anyone else.