"It's a matter of millimetres really," said ETNZ skipper Dean Barker after the day's racing. "You make a mistake and they just get stronger.
"Then on the downwind leg [Race 15] we just gave away too much distance."
Upwind is still a contest. OTUSA have looked faster upwind in recent races but the Kiwis did enough today to suggest they are more than competitive in that phase, cutting back OTUSA's big lead both times.
In Race 14, with OTUSA Jimmy Spithill having port entry, winning the start and forcing Team NZ wide round the first reaching mark, Oracle established a 24s lead after the downwind leg - gaining 18s on Aotearoa. Upwind, the Kiwis tacked efficiently, dragging themselves back into it, dragging the lead back from nearly 140m to 30m at one stage.
Then a slow tack, OTUSA found some tide relief and the lead lengthened again. OTUSA did two brave tacks to get the favoured journey round the mark - but the Kiwis found some good air and blasted up from 300m behind to within 30m, before the wind literally left their sails and the lead stretched back out to 300m again.
Team NZ had pulled up to 15s behind after the upwind leg but, with the American syndicate finding some good wind and riding the tide well, they stretched the lead again over the second downwind leg - that downwind speed again - and won going away by 23s.
Race 15 followed a similar pattern - Oracle running away before the wind, the Kiwis clawing them back into it. They were 60s down at the first downwind mark in Race 15 - a colossal amount. They did well to get back to 37s but the OTUSA crew are now sailing well and with confidence high.
They are making the right decisions and executing well; they are deciding when to split on the course and when to cover the Kiwis and deciding right. They are also having a bit of luck on their side.
When they sailed into a bit of a wind shadow in the upwind leg, it looked like Team NZ would catch them - but the wind came to their rescue.
Team NZ can still win this - but it is looking increasingly like they need OTUSA to make a mistake. There haven't been too many of those lately.
Even more worryingly, Race 15 was sailed in 16-18 knots of breeze - supposedly the Kiwi boat's sweet spot. But it was clear which boat found things sweeter today.
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