Easily the toughest achievement in Street Fighter 6.
The achievement description is misleading; you only have to win 10 Tournament MATCHES, not entire tournaments.
Tournaments occur 3 times a day (6:00am, 1:00pm and 11:00pm). However, tournaments DO NOT occur every day. Updates on how long tournaments run for are posted in the 'News' section of the Main Menu.
Depending on your skill level, try to enter tournaments with lots of people as that will increase your chances of being matched up with someone near your rank. Characters like JP, Guile, Manon, E. Honda and Zangief are good to use for either Modern or Classic Controls as Guile and JP have great zoning while the latter deal high damage in short bursts.
The maximum entry for tournaments are 32 players, but there are numerous tourney sessions to choose from, meaning you can potentially set-up a tournament where True Steam Achievement members can give each other wins.
IMPORTANT: Wins only count if you win a set (e.g. going 2-0 against a player will net you two wins) and receiving a bye in a round or your opponent disconnecting will NOT give you a win unless you won a game before they disconnected.
Good luck everybody! Took me 350 hours with some training to get every achievement, so make sure to hit the lab and practice
