For some time, the franchise of Naruto has shifted his focus from the older generation to the newer, in a series of events that led to the famous Will of Fire being passed down to the children of the ancient protagonists. However, there is still room for the old legends in the manga by Konoha Shinden and Sasuke Retsuden.
Long Before Boruto: Naruto Next Generations, Sasuke was involved in an important mission that could mean the life or death of his closest friend. The Seventh Hokage was stricken with a disease that affects the Jinchūriki, and only Sasuke can seek a solution to this problem at this point. However, the Uchiha is not alone in this mission as he was accompanied by Sakura.
In the same chapter of Naruto: Sasuke's Story where Sakura receives the engagement ring, there is also another moment dedicated to the Team 7 girl. Indeed it seems so Sakura didn't just learn medical arts from Tsunadeand that just one of those seemingly useless skills learned from her played an important role in the story.
In order to successfully complete their mission, Sasuke and Sakura had to wager at Star Lines, a gambling game in which the Kunoichi participate. Thanks to her, victory has come, that's why Sakura learned gambling techniques from Tsunade. In fact, the woman always checked all the cards for any signs of wear and scratches in order to remember them and have an easier life during the game. Sakura learned this skill and right now it came in handy to her thanks to the old deck used during the Star Lines game.
A nice move by Sasuke Retsuden's protagonist that allows the duo to progress on the important mission they want to complete.