These are quite obvious. To split 99 or 88 when dealer has an ace is just plain silly.
Key questions are:
When you have a 10 and dealer has a 10, do you double down?
When dealer has a 11, do you fold or buy insurance or just carry on?
When I have a 10, dealer has a 10, I hit till at least 17. That will guarantee losing lesser than hitting till 12-16 pts and wait for dealer to bust. The strategy of no busting before dealer is one of the lousiest strategy applied when we must know dealer's strongest cards are 9,10,j,q,k,A
When dealer have an ACE which is 11, 2 ways of playing.
if you are playing 1 hole, never buy insurance. Not worth it. because only 30% chance of dealer getting blackjack. insurance pays 2:1. So playing 1 hole, must try to hit your cards till at least 17pts. When dealer has an ACE, very seldom bust. Real life situation for me, dealer busting when they have an ACE is around 6%. That means 100 times, dealer has ACE, only about 6 times he will bust.
If you are playing a few holes, example 5 holes, then buying insurance is a good way to reduce losses.
if you have 5 holes in this sequence, 20pts, 18pts, pair of 33s, 16pts, 19pts.
let's say each hole bet $100. So total there is $500 worth of bets on the table. Dealer has ACE.
20pts hole can fight
19pts hole can fight
18pts hole maybe can fight
16pts cannot surrender because dealer has ACE. When dealer has 10,J,Q,K, 16pts surrender is already lose half better than lose more. It's a losing end card. So this 16pts must HIT.
pair of 33s, cannot split because dealer has ACE. 6 pts on hand, tendency to get 16pts is high because of 4 big 10s cards. getting 9 is 15pts, getting 8 is 14pts, getting 7 is 13pts. The situation is bleak.
This set of layout when dealer has ACE is to aim to leave this game losing less than $500. So will buy $50 worth of insurance.
If dealer hits blackjack, lose table bets $500 +insurance $100, total lose $400
If dealer hits 20, lose table bets $400 -insurance $50, total lose $450
If dealer hits 19, lose table bets $300 -insurance $50, total lose $350
If have no insurance, dealer hits blackjack, total lose $500
The only way to lose more than $500 is when dealer gets a 5, and gets another 5, total 21pts eat up all the bets + insurance bet. total loss is -$550
This scenario happens approx 10% of the time. So if you play 100 times, 10 times you will lose $50 more than the $500 you placed, but 90 times, you will save yourself from losing $50 or more. If can win anything out from this table, its a bonus. Rare but have also.