Always split aces and eights. That is one of the golden rules for blackjack players but not according to a friend of mine. He insists that splitting eights against a dealer upcard of either 9, 10, or ace is nuts because you are probably going to lose anyway, so why double your loss by splitting?
Although my friend’s logic appears to make sense it is flawed. Here’s why.

When you split in blackjack, you must bet more. That is a fact. The strategy of pair splitting, then, only makes sense if you end up either winning more or losing less vs. standing or hitting.
Losing less is often a hard concept for blackjack players to grasp. For example, you can expect to be dealt a 12 through 17 hand about 43 percent of the time you play blackjack. No matter what strategy you follow, the dealer will, on average, win more hands than the player will (with only one exception- a 17 vs. a dealer’s upcard of 6). Thus the best a player can do in a losing situation is to use a strategy that will allow him to lose less.

This is in fact the situation with a pair of eights against a dealer 9,10, or ace. If you hit the eights, you will lose on average about $52 for every $100 bet. That is quite a hefty loss, but it is what you probably expect when you hit a 16 (pair of eights). However when you pair split, you double your bet and play out two hands. A computer analysis of this situation shows you will lose about $43 per $100 bet. Still a bad situation from the players perspective. But would you rather lose $43 or $52? I hope you agree that the better strategy is to split the eights against the dealers 9, 10, or ace because you expected loss is reduced by $9 vs. hitting (and if you are thinking about standing on the 16 forget it! Your loss rate is even higher).
Overall a pair of 8’s is a lousy hand. Your objective in pair splitting is to improve your chances of winning some of the hands. When you split a pair of 8’s against a dealer upcard of 3 and 7 you will convert a losing hand into a winner. When you face a dealer’s upcard of 2, 8, 9 10, or ace, you will most likely lose BUT you will lose less then hitting or standing. The bottom line is that you are better off starting a hand with an 8 then with a 16.

Thankfully my friend always splits aces. You would think that every blackjack player would automatically split aces. But recently I observed a young player pass on splitting aces because “she was afraid to bet more on the hand”. I even offered to make the bet for her at no risk (if the bet lost she owed me nothing). But it was like talking to a wall. She insisted on hitting the pair of aces and drew two tens and broke. She was mumbling incoherently when she left the table knowing full well that if she had taken my offer she would have had two hands of 21 (by the way, I was card counting and the count was positive indicating she had a good chance of drawing tens to her aces.)

It use to be standard casino policy that when you split aces you would get one and only one draw card to each split ace. Sometimes the player would draw another ace and was stuck with a hand of 12. Nowadays many casinos allow players the opportunity to resplit aces. In the above example the player could split his third ace and play three hands. Resplitting aces is a favorable player rule that adds about .06% in the player’s favor. When a casino allows it, always resplit aces!

Follow the golden rule and always split eights and aces no matter what the dealer upcard happens to be. Splitting aces will result in significant gains for the player. Splitting 8’s for the most part is a defensive play that will cut down on your losses. But keep in mind you will lose your fair share of hands when you split 8’s, but if you were to hit or stand, you would on average be losing more money. It’s the smart play to make when you play blackjack.