The full extent of what Oracle did to change that crucial speed equation is not yet clear. Modifications were made to multiple aspects of its AC72, from the hydrofoils to the wing sail that was its primary power source. And unlike Team New Zealand, Oracle sailed with a new measurement certificate — reflecting changes to its boat’s configuration — for every race as it searched relentlessly for incremental improvements.

Russell Coutts, the most successful skipper in the Cup’s modern history and Oracle’s chief executive, shared some details, looking as relieved as he did delighted.

“The major changes in my view were the balance of the boat, where obviously the load sharing between the foils is critical, so we adjusted that quite a lot,” said Coutts, an engineer by education.

“We changed that loading by manipulating the wing shapes and flaps. So we didn’t actually change anything in a physical sense. We just changed the setting, so we more bottom-loaded the wing and more off-loaded that, and that created a different loading for the foils. And that was probably the biggest change we made.

“And then there were a bunch of little changes that just reduced the drag a few kilos here and a few kilograms there, and all the sudden you have an edge.”

Coutts said the other major factor was his team’s growing confidence in its yacht.

“Everyone talks about the technology: ‘What changes did you make?’ ” Coutts said. “The guys on board changed a lot. For sure there was a use of the technology change where we manipulated the force or manipulated the balance of those forces, but the guys on board the boat changed their technique, so there’s this fantastic human element to this which really won the day in the end, which is great.”