I'm curious about one point in the analysis of the second scenario where it is stated that the probability of facing split Kings has decreased because there are two visible K's on 3rd St instead of only one, but exactly the opposite is true. Then the analysis goes on with this false assumption playing a significant role. For instance the EV is calculated for the case of LdLdKd (where L=low) but not shown for LKK. I'll take a guess that it's probably not a play changer on 3rd, I'm just saying.

I agree that when there are two similar door cards in a stud or stud8 game the probability increases that one of the players has that card paired. In the article it is mentioned that the hero is in middle position, and the dead cards are listed out but there is no clarification on whether or not certain cards have been folded or are still left to act. If neither a king or nine had been folded before hero was to act then you are correct imo. If one king and one or both nines have both been folded before the action gets to the hero then, obv, it would decrease the probability of running into a bigger split pair.

The article should have been more clear on this point.