A question about the card game blackjack?

It's a matter of when there are mostly ten cards left in the deck then hitting has a high chance of going bust. As the player you don't have to hit so you could stand on 12 or 13 but the dealer will have to hit when his hand is less than 17 even when he has 15 or 16, he has to hit and with the deck being mostly 10's, even hitting on a 12 will go bust. It has nothing to do with you having a good chance of getting a 20 or a 21 on the first two cards. The odds are in your favour cause any hand stands a good chance of busting if hit and the dealer has to hit when under 17, you don't.