The 1st rule is to hit with 9 or below. After that you need to always double down with a 10 or an 11 unless the dealer shows a 10 or an ace. If you are holding between 12 and 16, it will be a little complicated but you will be able to hit it if the dealer has a 7 or higher. Having more than 17 should be stand out even if the dealer has it. There are other rules that can be applied if you want to increase your chances of winning. If you have numbers between soft 13 to soft 18, you can afford to double it down when the dealer is displaying a 5 or 6. But if you have a soft 17 or lesser than this, you should hit, and you can even get a soft 18 when the dealer is displaying a 6 or a higher number.