Toyota dockside in Bermuda: The smartest move Team NZ made

In this photo provided by the America's Cup Event Authority, Emirates Team New Zealand competes against Great Britain's Land Rover BAR (not shown) during America's Cup qualifying. Photo / AP.

The high-octane racing over the first week of the America's Cup has left a couple of the grinding teams a little exposed.

In this Cup, the guys doing the grunt work have a more significant role to play than ever before.

With the foiling catamarans being hydraulically driven, the way you generate the hydraulic pressure - or as the sailors term it, "the oil" - is through the energy output of the grinders.

Traditionally in sailing, the grinders are grinding sheets and ropes and winches, what we're seeing now is they're grinding to create hydraulic pressure and that pressure drives all the systems on the boat - whether it be controlling the rake and cant of the daggerboards, the rake of the rudders, and the adjustments of the wing sail.

Put simply, without hydraulics, the boat will not sail.

If the boats run out of hydraulic capacity, as we've seen in the races they have control problems. From my observations of the round robin racing thus far, Emirates Team New Zealand always look to be in control hydraulically. I can't say that about some of the other teams.

The two I have noticed in particular that have hydraulic-hungry boats, or the lack of capacity to generate hydraulic pressure, are Team Japan and Ben Ainslie Racing.

We saw that in the effect that the grinders, especially in the second half of the race and that brutal leg five upwind, got to the stage where instead on grinding down on their knees in a good arrow position, they ended up standing up. All their form had gone, we saw big shoulder rotation, and the grinders were out of gas.

In both instances the boats were affected because they can't foil properly and in the case of BAR's first race against Emirates Team New Zealand we saw a major touchdown and went from being quite close to the Kiwi boat, to being game over at the top of the first beat.

So what I'm seeing is, in the second half of the race especially on leg five, when there is a lot of fatigue kicking in, the New Zealanders are starting to look quite dominant.

It's probably about that stage in the race Team NZ will be feeling pretty good about their decision to plump for pedal power.

Because the boats are so damn hungry on hydraulics, I would say the cycle-grinding has been one of, and I stress one of, the contributing factors to Team NZ's early success.

The more I see it, the more I think it was a really smart move from Team NZ. Smarter still, they held it back and made it really hard for the others to replicate. It's not a last-minute thing you can knock together. The Oracle set-up that we have seen with tactician Tom Slingsby pedaling at the back is very much a hybrid - it's like a kid's bike on training wheels.

But in saying that we haven't seen Oracle have the hydraulic shortages that some of the other teams have had, which suggests that their system is working for them.