Need Help Designing Tennis Ladder Database
This looks good, except I would combine the Ladder_Users table with the UserLadderStats table. There's no reason to have them separate and it just introduces the chance for data integrity problems. Just move all the stats onto the Ladder_Users, and then you can drop UserLadderStats.

Also, note that the WinnerUserID and LoserUserID in LadderMatch are foreign keys, even though they aren't explicitly marked as such.