Very common scenarios in casinos. When ppl see dealer have a 10s as first card, they hit and hit. When they see small face values like 2,3,4,5,6, they stand and hope dealer bust, or double-up their cards. As you notice, chances that dealers that have A or small value cards seldom go bust.
No one can predict the next card, but if you work out the probability enough, even dealer has strong starting card, there is no need to be afraid of them. That's why I go casinos with a "fresh body and clear mind". Once I feel physically drained, I go home and Zzz...
=================================================
It depends.. on the card that the banker has opened. If the card is anything less than 7, ie 6 and below.. and not an ace... (from 2 to 6), then even with 12/13 points you can probably try not to draw a card if you are the first few players.
If you are the last, it could be different.. depending on the sequence of cards that came out before you.. is the next card likely to be a 10 and above? the trick is to leave the 10 or picture card for the banker if the banker only as a few points.. 2 picture will kill him and pays everyone.
If however, if the banker has a ace or 10 or big cards.. if you have only 12/13 points, most likely you may want to draw a card to improve it.