America's Cup
Was it the rudder? Maybe it was the flukey winds? How about how many wheat biscuits the grinders loaded before the America's Cup that Oracle Team USA emphatically snatched from the grasp of Emirates Team New Zealand?
Well, yes and no. You are getting warmer but the engineers from the two crews last night shed some light on the emotional and mental rollercoaster ride they rode before one clinched the sport's oldest silverware at San Francisco Bay last September.
"It's not that simple. There were incremental changes," explains Neil Wilkinson, a Kiwi-born engineer with the Oracle team who came from 8-1 down to win the last eight races, to the dismay of Team NZ skipper Dean Barker and his crew.
"The boat kept improving from race seven but the crew were also learning from watching the opposition.
"The fundamental thing people saw was the Oracle boat couldn't match the New Zealand one upwind from the beginning of the regatta," Wilkinson says of the Jimmy Spithill-skippered Oracle, which showed signs of deterioration as the campaign wore on.
Wilkinson and his Team NZ counterpart, Andy Kensington, also of Auckland, were on the last leg of the "Battle of the Boats" free lecture at Napier War Memorial Conference Centre, after trips to five other centres from Whangarei to Dunedin to debate factors such as the impact of technology.
The Institution of Professional Engineers NZ hosted it to celebrate its centenary year.
Wilkinson says the Kiwis won four races of the 34th cup before "good luck" saw the hosts pull one back.
It became blatantly obvious to both parties they needed to work on the upwind mode.
Testing had revealed to Oracle engineers that they could improve but there were downsides to it.
"It was much more difficult for the crew to trim the wing [the main sail].
"There were higher loads on the structures [more danger of something breaking]," Wilkinson explains, adding they started with 1.5 tonnes of pressure but ended the regatta with two times as much.
Not only was the equipment not geared to absorb that intensity but the crew had to shoulder that load in employing the muscles of their grinders.
At that stage Oracle took advantage of a few "lay days" to make changes.
"We had to achieve the remoding of the wing sail ... and its control system."
That did not include the boatbuilding overnight and cutting away carbon-fibre structure to generate "new stuff".
"They weren't major but minor stuff that took hours and hours through the night to do so the shore crew [boatbuilders] were very heavily loaded, too."
Before they matched up against Team NZ, the champions thought they were compatible in just about all facets.
"Our boat was designed from the very beginning to have a low aerodynamic drag. It was very clean, it was smaller in many ways than Team NZ and didn't have much rigging under the platform."
The result, though, up to the middle stage, knocked the stuffing out of their upwind sails, as it were.
The engineers scurried to their drawing boards to look at the "engine" (wing sail).
"Obviously it wasn't working to its potential and perhaps we hadn't got the tuning right, like that of a car."
That prompted Oracle engineers to tinker with the twist of the wing sail in a bid to find the centre of effort where the wind found traction, to channel it lower down to the platform.
No one pointed fingers and the crew understood the repercussions of the modifications.
"They were already producing an enormous amount of power from humans to control this beast but that is what everyone's paid for."
Wilkinson lauded Spithill as a "tremendously focused and determined person", something which rubbed off on the crew.
"They were not conceding that there was no hope of winning at any point and that we can win this."
From race 8, Team NZ made a minor error and almost capsized, signalling to engineers the Oracle boat was showing its potential in pushing the Black Boat to its limits.
"We made our luck in one case and refused to compete in the second race," he says, accepting forfeiting that race did not go down too well with the public.
"The modes we exposed that day weren't fruitful but we learned that we didn't need to go down that track."
Another stroke of luck came when Team NZ ran out of time in race 13 because of fickle winds. In the re-run the wind gods smiled down on Oracle.
"They were 50 seconds or so away from winning the race and the cup too, but it wasn't to be."
Lady Luck sang Oracle's tune. So did the "systematic tuning". And don't forget the determination of the crew.
Married to Californian "girl" Kelly Ann, Wilkinson hastens to add as a family they have varied allegiance.
"A lot of economic benefit came to New Zealand because of the structural building of Oracle," he says, emphasising the Warkworth facility is still there. "It's like Formula One, so it's not so fervently national."
What about money?
"In final weeks, even if you had billions of dollars lying on the table, it wouldn't have made any difference. You just can't buy that sort of result."
But Larry Ellison's booty goes a long way.