The Tournament matchmaking follows a specific rule that takes into consideration (in the following order):
  1. The player's highest achieved League*
  2. People that are searching at the same time

*If no opponents from the same highest achieved league are found, the game will look for opponents in lower Leagues.

There is multiple instances of a tournament, so you can play against other opponents in the same tournament league but they might not necessary be in the 100 grid.

And what is the Level Cap?

As you should know, your Lineup is composed by the cards you have equipped in your lineup tab, meaning your choice of tennis player, racket, grip, etc. And each of these cards can be upgraded individually, increasing their level and how much they affect your attributes.

The level cap evens out all lineup cards to the specific level cap for each tier in order to allow players to have a fair and fun experience in the Tournaments.

Each Tournament tier has its own level cap as detailed below:
  • Rookie: level 6
  • Junior: level 9
  • Challenger: level 12
  • Master: level 15
The level cap is also described in the Entry button for each Tournament Tier.

Here's an example:
A Player who has a card beyond level 5 in their lineup playing Rookie Tier in the Tournaments will have their cards downgraded to level 5 only during all Tournament rounds. Players with cards below level 5 will keep the original card level.