Stud high low is one of my favorite poker games because it promotes players to tilt, and tilt badly. If you are a huge mental game fish I would highly suggest not playing the game as in no other form of poker does the structure require you to draw and basically stay in until the end—no matter how extreme the action—when you catch certain cards. For example, if you start with A♠ 2♠ 4♠ and then catch a 5♠ on fourth street you are staying until the end no matter how many bets you face or how much money is shoveled into the pot. You can imagine how crazy people get when they call an additional ten big bets on fourth, fifth and six streets to be only dealt the K♦, Q♣ and 9♥. I have literally seen people crunch and break the river card on multiple occasions.
But besides the ability to keep it cool in hands after these types of situations occur, similar to no limit, great players have higher winrates because of thin value betting, specifically on seventh street. Stud 8 hands play out even more straight forward than straight stud hi hands because of the fact that for straight high opening hands it is rarely correct to semi bluff. A lot of the time you will end up chopping the pot and if your opponent catches a good card by fifth street you rarely have any fold equity no matter how strong your high board looks (because your opponent is going for low). This means that when a player raises with a K up with several other low cards behind him on third street there is a VERY good chance that he has split kings or a buried high pair. In stud high a player could be raising with a hand like K♥ 9♥ 3♥ if the king is the highest card on the board. That dynamic does not exist in stud hi low. So most of the time a high hand actually has what they are representing.
What this means is that if you start low a high hand will often call you on the river, if he makes it that far, in order to try and chop the pot. This makes it an almost mandatory bet for us with two small pair on seventh if the high player does not have a pair on his board.
Let us take a look at an example to make it clearer. We are the bring-in (low card) with the 2♣ and it gets folded around to a player with the Q♠ up who raises with several low cards behind him. The player is solid so there is about a ninety nine percent change that he has a high pair. It gets folded to us and we call with 2♣ 5♣ 6♦. This is a fairly strong starting hand in Stud 8 but is a dog to split queens right now so we just call. On fourth street we catch the 5♦ to pair up and our opponent catches a T♣. He checks (high acts first) which is almost always correct against our 25 board, we bet and he calls. On fifth street we catch a 8♥ and he catches a 6♣. He checks, we bet and he calls. On 6th street he catches a 9♠ and we catch a bricked J♦. He checks to us again and this time we decide to check it back knowing that we are a slight dog to a pair of queens. On 7th street our opponent checks to us (again the right play as we could raise him at the end with any low or high hand that fairs to beat him and he would be forced to pay off) and we look down to see the 2♥. We have backed into two small pair with fives up. Our opponent is not showing a pair on his board and is very likely to have split queens. He will also pay us off with a pair of queens because it is so likely that we have a low and he wants to chop the pot.
This value bet with two small pair is where the men are separated from the boys in stud hi-low. Yes, we could end up value owning yourself and lose to queens up but a bet here on the river is correct if we think when called we are good more than fifty percent of the time. For the reasons stated above our opponent is almost always calling us with just a pair of queens so this would be a profitable bet.