This question can only be answered within the context of the counting system being used, and you have not provided that. My question is: how much does each extra king of spades change the TC threshold requirement for a positive EV?

Side note: I think this a great cover bet for counters, since a big win on KB would excuse you to just being lucky in the casino's view, I've had marginal results to date but ultimately anticipate a big payoff. Once to TC>+5, I bet on all neighboring squares (if player allows) at $5. My bet range has been $1 on each betting square, progressing by $1 more for each TC greater than. I have played it when TC has been at the insurance TC requirement or greater (>+3) combined with the remaining decks being somewhat rich in K spades.

My question is: how much does each extra king of spades change the TC threshold requirement for a positive EV? ie say 3 of 6 decks dealt and there are 4 Kings of spades (or even 5 or 6), versus 3 Kings of spades remaining. However, assuming the count of Kings of Spades is rich in the remaining deck(s), the TC must certainly be adjusted accordingly. In reviewing the cutoff for a positive EV and TC requirement on some BJ sites, I've seen the bet is around a 15% house edge at the start of a 6-deck shoe, and only returns a positive EV when the TC is >+8. I recently encountered the above mentioned Kings Bounty Side Bet in a 6 deck game. For a hand of unsuited total 20 player is paid 4 to 1 2 Kings pay 6 to 1 Suited 20 pays 9 to 1 2 suited 10’s, Jacks or Queens pay 20 to 1 2 suited Kings pay 30 to 1 2 Kings of Spades pay 100 to 1 and 2 Kings of Spades against a dealer blackjack pay 1000 to 1. Kings Bounty blackjack is a special Side bet on first cards dealt to player and the dealer.

King's bounty blackjack horseshoe