What happened: The World Cup has reached its Round of 16, moving the tournament from group play into single-elimination knockout soccer. Sixteen sides remain alive as the field narrows toward the quarterfinals.

Why it matters: The knockout stage raises the stakes on every match: a single loss now ends a team's run. It marks the point where group-stage form gives way to win-or-go-home pressure and the margins between advancing and elimination shrink.

What to watch: Watch for the Round of 16 fixtures to set the quarterfinal bracket as each result eliminates one more side from contention.