As I said, I liked this episode, but I will agree with the rest of you that it was confusing.

It helped for me that I was familiar with the "gambling junket" business, which still exists today. For the viewer not understanding junkets, that just adds another level of complexity to an already confusing story.

Junkets are trips where a "gambling travel agency" books people on trips to casinos, often covering all or most of their expenses. It is attractive to the gamblers because they can go to far-flung locations to gamble, and automatically get things comped without having to establish a history at those casinos. It is attractive to the casinos, because the junket operator brings in compulsive gamblers who are likely to lose a lot of money. The junket operator actually gets paid by the casino, usually in the form of commission of either a percentage of total losses or a percentage of "expected loss", which is calculated based upon the total amount bet and house edge.

Hawaii is one of just two states in 2023 with no legal gambling. The other one is Utah. However, in 1973, it was a different story. Gambling was also illegal back then, but there was only one state where you could gamble at the time -- Nevada! There wasn't even gambling in Atlantic City yet. That showed up in 1978.

Sam's junket business was not illegal, nor are any junkets. Sam was simply arranging trips for gamblers on the island, whose choices to gamble involved either flying thousands of miles, or to gamble in an illegal operation like Yoshigo's. Yoshigo seemed upset that Sam had his junket business, but in reality it's not that likely this would dip into Yoshigo's earnings. Even those taking Sam's junket trips would also have a desire to gamble without flying thousands of miles to do so. I also wonder how lucrative Sam's junket business would be, given that there was substantial expense to take these long flights in 1973. Therefore, Hawaii's fairly low population probably would not have produced many high stakes gamblers who would have been necessary for the casinos to cover their travel expenses. The average low-stakes gambler is not going to get a free junket trip from someone like Sam -- not from Hawaii! (There are cheaper junkets in the mainland, especially nowadays, where you are slapped onto a charter flight and flown 600 miles to some crappy casino.)

But if we put aside that junkets weren't doing brisk business in 1973 Hawaii, the story itself here was interesting, and the episode was a whodunit, rather than one where we see the perpetrator at the beginning. Sure, we knew Yoshigo had that old guy murdered at the beginning, but the real mystery was who killed Howard, and why. The answer we got at the end wasn't all that obvious, and it wasn't all that far fetched, either. From that standpoint, I really enjoyed "Percentage".

Where the episode got needlessly complex was the whole side story with Yoshigo's accountant Stein. Not only was Stein's role with Yoshigo not clearly explained, but the entire "demotion' he received for blackmailing Yoshigo was awkward and somewhat ridiculous. Stein was nervous throughout the entire episode, and really didn't serve much of a purpose in the story, other than to complicate things. Milton Selzer's Sam character and Leonard Stone's Stein character seemed to play to the tropes of older Jewish men of the era, with Sam being the shifty operator, and Stein being the ne'er-do-well schnook. The actors playing them were both Jewish, by the way.

When Valerie Sinclair is disgusted with her much older husband Walter for having paid Sam to murder her lover Howard, she yells at him, "You murdered him. And we both know why. Because he gave me what you never could, you old, old man."

Presumably Walter was impotent, and she was having the affair with Howard because he was able to have sex with her. The "you old, old man" line was a bit awkward, though, and in real life would have been something like "you impotent old man"!

But how old was Walter? The actor (Douglas Kennedy) actually was only 57 -- just 6 years older than I am today. His last acting roles were appearances in three late-Season-5 episodes -- "Here Today... Gone Tonight", "Percentage", and "Jury of One". He was not from Hawaii, but he died there of cancer in August 1973. Apparently he got sick enough after being done shooting to where he was not healthy enough to return to the mainland, and chose to be treated in Honolulu. It's unclear if he knew he had cancer before shooting these episodes. Many people in those days did not visit the doctor when feeling lousy, and just toughed it out until things got really bad.

Carole Kai, who played Valerie, was 29 years younger than Kennedy. She was born in 1944, and was 28 or 29 when the episode was shot. She's still alive today, and is the only person from that episode who hasn't passed yet.

Howard was Valerie's virile alternative to her "old" husband, but in reality the two men were just six years apart. It would have made more sense if Valerie was cheating on her husband with a man closer to her own age, as this is what commonly occurs when an older man marries a young woman, and infidelity occurs.