On tiny details can great victories be won.
Team New Zealand made two mistakes yesterday and it cost them a loss by 31s. But while there was deserved attention being paid to Oracle Team USA's boat speed and handling, the Kiwis ended up demonstrably behind at the start - outdone by Oracle skipper Jimmy Spithill's hook manoeuvre - and admitted later they might have got it wrong in setting up their boat.
The AC72s are so responsive to change that they are like a highly strung racehorse; the wrong bridle or the lack of blinkers or the wrong jockey and performance is impaired. So setting up the boat for the conditions that apply is an educated guess on what will work best in the combinations of wind, tide and current.
Emirates Team NZ admitted to setting up their boat wrongly yesterday but skipper Dean Barker said that wasn't the reason they lost the race.
"The start did that," he said. "When you change the boat, you try to match it up to the conditions that are forecast.
"But the breeze got up quicker than we anticipated and maybe we weren't optimised as we would have liked. You never get it 100 per cent right.
"We will be going to get amongst it and fight hard for the one race we need - and we'll do that all the way to the end. But it will not be easy.
"These guys [Oracle] have improved and it will not be an easy task to get another point off them. We have said this right from the start - there are no gimmes and this is a real battle and we are going to have to sail well to win races. Nothing has changed since the beginning of the series.
"If we sail as well as we should, we will win a race."
A help today will be having port entry at the pre-start. In the outgoing tides that have prevailed lately, port entry to the pre-start has been the favoured spot as the skippers duel for position before the race begins.
A port position helps with the drag race off the line to the first reaching mark; the boat on starboard has to have achieved overlap before it can gain right of way around that mark - and the likelihood of being in a position to control the race.
Oracle skipper Jimmy Spithill said: "A lot depends on where the current is going and the wind speed but I think it's fair to say both teams are learning more and more with every start.
"You know, if you add up the number of races we've done in the AC72s, there's quite a small number.
"More good starts seem to be gained through port entry - but that's not to say starboard entry can't win races as well."
On the all-important weather front, the forecast is for lighter winds than yesterday, maybe 11-14 knots but with a less impactful tide, meaning slightly higher wind limits are likely.
This is the point we would normally say that would benefit one team or another but they are so adept at optimising their boats to wring maximum advantage out of the conditions that it is probably more helpful to say nothing.