1

How the 2013 Louis Vuitton

Cup was won

Gaetan Lion

San Francisco August 2013

2

Introduction

In August 2013, two teams Emirates-New Zealand and Luna Rossa-Italy competed in a best of 13 series. New Zealand won 7-1. They only lost one race due to a mechanical failure.

The match up was plagued by mechanical failures affecting both teams.

However, 5 races were unaffected by such troubles (Race 4 to Race 8).

Analyzing those five races confirm two things:

1) the New Zealand boat was much faster;

2) the New Zealand team sailed much better.

3

Two metrics

We concentrate our analysis on two metrics:

1) The avg. Boat speed/Wind speed multiple. If the wind clocks at 10 miles per hour and the boat goes at 20 mph. This multiple is 2. Obviously, boat speed is a key advantage. You want this multiple to be as high as possible;

2) Sailing efficiency. This equals sailed distance/Course distance. A figure of 200% would indicate a boat sailed twice as long a path as the course distance. You want this number to be as low as possible and as close to 100% as possible.

4

Sailing Efficiency Average

wind speed Sailing Efficiency

in knots NZ Italy NZ advantage

Race 4 14 113.0% 114.9% -1.7%

Race 5 13 113.0% 114.9% -1.7%

Race 6 14 112.6% 115.5% -2.5%

Race 7 18 111.2% 112.2% -0.9%

Race 8 11.5 116.0% 119.9% -3.3%

The New Zealand team (NZ) sailed much better in all different wind

speed ranges (from very slow at 11 knots to close to the wind speed cap

at 18 knots).

This translated into an advantage of 1 to 3%. Given that the races were

typically around 25 minutes long. If the two teams had the exact same

boats, the NZ team would win by a range of 15 to 45 seconds because of

more efficient sailing (shorter sailed distance).

The only way the Italian team could overcome this handicap is by having

a boat that is 1 to 3% faster than the NZ one.

5

Sailing Efficiency vs Wind speed Wind speed vs Sailing efficiency

111%

112%

113%

114%

115%

116%

117%

118%

119%

120%

10 12.5 15 17.5 20

Average wind speed in knots

Sa

ilin

g e

ffic

ien

cy

(d

ista

nc

e

sa

ile

d/c

ou

rse

dis

tan

ce

NZ

IT

Same info as shown on previous slide. NZ is far superior and invariably

much closer to the ideal figure of 100% (sailing exactly the same distance

as the course which is impossible).

6

Boat/Wind Speed Multiple

Average

wind speed Speed multiple

in knots NZ Italy NZ advantage

Race 4 14 1.92 1.81 6.5%

Race 5 13 2.19 2.10 4.2%

Race 6 14 1.77 1.71 3.8%

Race 7 18 1.62 1.52 7.1%

Race 8 11.5 1.85 1.74 6.1%

Regardless of wind speed conditions, NZ’s boat was faster

than the Italian one (from 4% to 7% faster). Assuming both

teams would have identical sailing performance, the faster NZ

boat would translate into wins ranging from 1 minute to 1

minute and 45 seconds. Those are huge win margins on a

course that takes typically around 25 minutes.

7

Boat/Wind Speed Multiple scatter plot

Wind speed vs Boat speed/Wind speed multiple

1.50

1.75

2.00

2.25

10 12.5 15 17.5 20

Average wind speed in knots

Avg

bo

at

sp

eed

/Avg

. w

ind

sp

eed

mu

ltip

le

NZ

IT

Same info as previous slide, but shown visually.

8

Combining Sailing Efficiency

& Boat Speed

New Zealand Time Savings

Combined Combined

Sailing eff. Boat speed Calculated Actual

Race 4 -1.7% -6.1% -7.8% -8.0%

Race 5 -1.7% -4.0% -5.8% -5.7%

Race 6 -2.5% -3.7% -6.2% -6.5%

Race 7 -0.9% -6.6% -7.5% -7.7%

Race 8 -3.3% -5.8% -9.0% -9.0%

As shown, New Zealand won all 5 races by huge margins

representing from 5.7% to 9% of the elapsed time. That

would be like winning a 100 meter running race by between

57/100th to 9/10th of a second (ridiculous winning margin).

9

Combining Sailing Efficiency

& Boat Speed scatter plot

Boat speed/Wind speed multiple vs Sailing efficiency

1.4

1.6

1.8

2.0

2.2

2.4

110% 112% 114% 116% 118% 120% 122%

Sailing efficiency

Bo

at

sp

eed

/Win

d s

pe

ed

mu

ltip

le

NZ

IT

The optimal quadrant is the upper left one. And, NZ has

always a better optimized position close to this quadrant.

10

Weighing NZ crew vs boat

performance

Boat Crew

Race 4 78.2% 21.8%

Race 5 70.3% 29.7%

Race 6 59.5% 40.5%

Race 7 88.4% 11.6%

Race 8 64.0% 36.0%

Average 72.1% 27.9%

In average, the NZ team won because of superior boat

speed (72%) and because of superior sailing efficiency or

crew (28%).

11

Conclusion • The final of the 2013 Louis Vuitton cup

was not competitive. The NZ team wiped

out the Italian one on all counts;

• Nevertheless, it was a very interesting

experiment in sailing AC 72 catamarans at

peak speeds up to 47 knots or 54 mph!