You should always split 8s, even against a dealer's ace. Splitting 8s allows you to create two hands starting with an 8, which gives you a better chance to improve your position. Holding a total of 16 against a dealer's ace is unfavorable, as you're likely to lose more often than not. By splitting, you increase the potential for creating a stronger hand, giving you better odds in the long term, despite the risk associated with the dealer's ace. This strategy is rooted in the mathematical probability of benefiting from splitting in blackjack.