VALENCIA, Spain-The subtle changes in yacht races that make the difference between victory and defeat are often hard to detect. In the four race of the 32nd America's Cup Alinghi's helmsman, Ed Baird, accelerated for 18 seconds before the start, while Emirates Team New Zealand's helmsman, Dean Barker, slowed down to avoid jumping the gun. The next 4 seconds set the stage for the rest of the race. Alinghi was fast and ETNZ struggled to gain speed. Click on their names to hear Barker and Alinghi tactician Brad Butterworth offer their perspectives on the start.At the starting gun NZL-92 was one knot slower, allowing Alinghi to grab a small, but significant, one boatlength lead. From that moment Team New Zealand was in catch-up mode. It was a painful day for Kiwi fans. There was one good opportunity for NZ to catch up, but the crew let it slip away. Not surprisingly, Butteworth was was much happier with today's conditions.Alinghi drove Team New Zealand out to the lay line on leg one and rounded 20 seconds ahead at the first mark. On leg ETNZ blew a jibe, and wrapped their spinnaker around the headstay. This kind of mistake is usually caused by the helmsman not turning in sync with the position of the sail. Error charged to Dean Barker. He talks about the problem in this audio clip. Alinghi stretched out to a 34-second advantage. However the Swiss team had a difficult rounding and came out of it quite slow. Butterworth and Hutchinson offer their thoughts on the leeward gate in this audio clip.On the third leg New Zealand sailed to the left side of the course while Alinghi headed to the right. Every Swiss fan on our ship, Silver Whisper, was screaming for Alinghi to tack and cover. They were mindful how Alinghi let Team New Zealand off the hook in Race 3 on the final leg by not covering. The New Zealand team went on to win a thriller yesterday. Would Alinghi's tactician Brad Butterworth repeat the mistake?Finally, Alinghi tacked. Emirates Team New Zealand had the left side of the course to work with. The wind was forecasted to go right so ETNZ tactician Terry Hutchinson was on a wing and a prayer. But then halfway to the windward mark, Alinghi's wind dropped and their boat slowed. Team New Zealand got a heading puff of wind. Suddenly they were even. Surely Hutchinson would call for a tack back toward Alinghi. This was the big moment. But Team New Zealand continued on. Now the Kiwis fans were urging their team to tack. I felt like I was at a Redskin vs. Cowboys game where spectators scream for their team to cover an open downfield receiver. Alinghi's owner, Ernesto Bertarelli, watched intensely from the leeward side of his boat. You could see by the expression on Bertarelli's face that he was hoping Team New Zealand would not tack. After about a minute the wind returned and Alinghi started gaining. Team New Zealand blew it. They had the opportunity to draw even. Hutchinson explained what was going through his mind at the time during the post-race press conference. Throughout the rest of the race the Kiwi team tried tacking duels and then jibing duels to pass. Alinghi matched every move. Butterworth was sailing right out of the textbook. In the end the margin was 30 seconds to Alinghi.The score now stands 2-2 in this best of nine series. Here is what we have learned to date: Alinghi has a slight edge upwind. Under 11 knots NZL-92 is about the same speed. Both crews have made a few small, but costly, mistakes. The margin of error is tiny. For this reason there will be a lot more theatrics in the rest of this regatta. Ed's Note: At the end of racing both boats were told they would be measured and requested to not hoist anyone up the rig to drop the main. According to the rules the teams must be able to take the main off the lock and lower the mainsail to the deck without hoisting anyone up the rig. To avoid the extra weight of a main halyard both teams use the spinnaker halyard looped over the tip of the mast to raise the main, then put it on lock, and return the spinnaker halyard to its original function. Reportedly, Team New Zealand has an ultralight line it uses to lower the sail. Alinghi apparently does not. So they requested that they be able to attach the spinnaker halyard to the main and leave it loose, then blow the lock. That way the main wouldn't come crashing down on the deck. But supposedly, if they needed to, they could do just that. You can hear two views on this part of America's Cup Class design from Murray Jones of Alinghi, and Don Cowie of Team New Zealand. Just before the protest time expired Team New Zealand filed a protest regarding this rule. It will be heard tomorrow at 11 a.m.