According to Jack Lord, Hawaii Five-O's quality made it too good to fail

Some shows have what it takes to succeed, and others fail from the start. Does an actor's confidence in a series help the odds of it doing well? No, but it doesn't hurt for fans and critics to see the star bragging about it being good. Jack Lord already built an impressive resume before starring as Steve McGarrett on Hawaii Five-O.
However, the series was one of his greatest additions, and his confidence that it would succeed before it was even renewed for a second season was the icing on the cake. Lord knew that his crime drama would be special because it was on a different level than others. For starters, it was filmed on location in Hawaii. According to a 1968 article in The Sun, Hawaii Five-O was filmed in all parts of the island, and each segment featured about 35 to 40 different locations.
"This show is going to make it; I don't see how it can fail," Lord said in the article. "This show has quality. The proof of that is the number of CBS-affiliated stations that signed up to take 'Hawaii Five-O'. We showed the pilot film to them, and 206 ordered the show, the biggest number in CBS history. A show like Carol Burnett's only has 163."
While the beautiful scenes make for something nice to look at, great scripts were still imperative to keep viewers coming back. Lord said that at the time, executive producer Leonard Freeman was policing the scripts with expert care. "He even ordered and paid for three scripts — and then threw them out because they weren't good enough."
The article states that throwing out scripts that were already paid for was rare in television during this time. While filming a new show in Hawaii was surreal, it also meant Lord worked long hours.
"Last week I worked 83 hours. The only thing that saves me is the Screen Actors Guild ruling that you must have a 12-hour rest period before being called back to work...I came here to work, and I think the results are going to be worth it."