>>536722224
>deal in rate higher than win rate
This are the stats you need to work on the most.
To increase your win rate, just try to get to a good tenpai faster than the other player ; train your tile efficiency. You'll get it as you continue playing and doing WWYD exercices.
To decrease deal in rate, just fold lol. Remember mahjong is a 4-player game, you're supposed to win 1/4 game. The 3 game you don't win try to make them games you don't lose (deal in). When to fold and not to fold is nuanced but in silver you can strictly follow pic related and you'll be good.