Semi-Final Speed Comparison spreadsheet

by Andrew Wilson on 1 Jun 2007
Sail-World reader Andrew Wilson has analysed the relative performances of the Louis Vuitton Cup Semi-Finalists and has extended this into an insight of what we can maybe expect to see in the finals of the Louis Vuitton Cup

He concludes:

Upwind ETNZ's boatspeed was 0.09kn faster upwind than Luna Rossa, although L.R. reached the top mark 26 seconds earlier,(or about 5 boat lengths) however ETNZ had an average of 3.25 extra tacks per leg (42% more) and seemed to cover and attack more.

Downwind ETNZ's boatspeed was 0.14kn slower downwind than Luna Rossa with L.R. completing an average of 2.2 (43%) more gybes per leg, however all four boats were only separated in avg. downwind leg time by 4 seconds (less than a boat length) possibly suggesting different pointing angles and more even VMG's (Velocity Made Good, i.e.- Speed toward the Mark)

Who is Quicker??? - Emirates TNZ vs. Luna Rossa
Semi Finalists Statistical Comparisons
23/05/07 - by Andrew Wilson
andrew@partform.co.nz
ph: +64274060142
Note: While These statistics are an interesting comparison of speed averaged over 6 Semi Final races, they cannot be relied upon as a truly accurate indicator
of relative speed due to differences in windspeed, upwind and downwind pointing ability, number of tacks / gybes and tactical sailing manoeuvres.
However, as these Semi Final races were sailed on the same courses starting within 10mins of each other, the wind and sea conditions should be similar and
the greater the number of races sampled, the more accurate the averages should be. Data was accumulated and interpreted from published Americas Cup Management Race Timing Sheets
…statistics don't lie, interpretations do!...
	Emirates TNZ						Luna Rossa								Oracle BMW					Desafio Espanol
Race 6													Race 6
MARK	Elapsed Time	Leg Time	Avg. Speed	Tacks/Gybes	Wind		Elapsed Time	Leg Time	Avg. Speed	Tacks/Gybes	Wind		MARK	Elapsed Time	Leg Time	Avg. Speed	Tacks/Gybes	Wind		Elapsed Time	Leg Time	Avg. Speed	Tacks/Gybes	Wind
Start	0:04	-	-	-			0:02	-	-	-			Start	0:01	-	-	-			0:02	-	-	-
1st Windward	25:19	25:15	9.4	10	12		24:31	24:29	9.4	9	13		1st Windward	25:03	25:02	9.3	10	13		25:07	25:05	9.5	10	12
1st Leeward	42:54	17:35	11	2	15		41:23	16:52	11.8	4	14		1st Leeward	41:55	16:52	11.7	5	14		42:41	17:34	11	2	15
2nd Windward	65:39	22:45	9.7	10	15		63:49	22:26	9.5	8	15		2nd Windward	64:24	22:29	9.6	7	15		65:31	22:50	9.6	8	15
Finish	84:48	19:09	10.7	1	14		82:34	18:45	11.6	9	13		Finish	83:07	18:43	11.7	9	13		84:33	19:02	10.7	1	14
Race 5													Race 5
MARK	Elapsed Time	Leg Time	Avg. Speed	Tacks/Gybes	Wind		Elapsed Time	Leg Time	Avg. Speed	Tacks/Gybes	Wind		MARK	Elapsed Time	Leg Time	Avg. Speed	Tacks/Gybes	Wind		Elapsed Time	Leg Time	Avg. Speed	Tacks/Gybes	Wind
Start	0:03	-	-	-			0:24	-	-	-			Start	0:14	-	-	-			0:04	-	-	-
1st Windward	27:05	27:02	9.2	19	10		26:33	26:09	9.2	12	8		1st Windward	26:58	26:44	9.1	16	8		27:40	27:36	9.2	21	10
1st Leeward	49:18	22:13	9.6	4	8		47:43	21:10	10	8	8		1st Leeward	48:31	21:33	10.1	7	8		50:13	22:33	9.6	5	8
2nd Windward	77:14	27:56	8.7	12	7		74:41	26:58	8.9	8	6		2nd Windward	75:35	27:04	8.9	9	6		78:29	28:16	8.8	11	7
Finish	103:42	26:28	8.8	4	8		101:18	26:37	9	5	7		Finish	103:15	27:40	9	7	7		105:31	27:02	8.7	4	8
Race 4													Race 4
MARK	Elapsed Time	Leg Time	Avg. Speed	Tacks/Gybes	Wind		Elapsed Time	Leg Time	Avg. Speed	Tacks/Gybes	Wind		MARK	Elapsed Time	Leg Time	Avg. Speed	Tacks/Gybes	Wind		Elapsed Time	Leg Time	Avg. Speed	Tacks/Gybes	Wind
Start	0:04	-	-	-			0:02	-	-	-			Start	0:03	-	-	-			0:08	-	-	-
1st Windward	27:40	27:36	9.3	29	10		26:19	26:17	9.3	17	11		1st Windward	26:32	26:29	9.3	17	11		28:05	27:57	9.2	28	10
1st Leeward	46:14	18:34	11.1	2	10		44:26	18:07	11.1	4	11		1st Leeward	44:38	18:06	11.1	3	11		46:44	18:39	10.9	3	10
2nd Windward	70:22	24:08	9.2	16	10		67:02	22:36	9.4	2	10		2nd Windward	67:31	22:53	9.5	3	10		71:09	24:25	9.3	15	10
Finish	90:51	20:29	10.8	5	10		87:44	20:42	10.6	11	10		Finish	88:07	20:36	10.7	12	10		91:33	20:24	10.9	5	10
Race 3													Race 3
MARK	Elapsed Time	Leg Time	Avg. Speed	Tacks/Gybes	Wind		Elapsed Time	Leg Time	Avg. Speed	Tacks/Gybes	Wind		MARK	Elapsed Time	Leg Time	Avg. Speed	Tacks/Gybes	Wind		Elapsed Time	Leg Time	Avg. Speed	Tacks/Gybes	Wind
Start	0:03	-	-	-			0:01	-	-	-			Start	0:02	-	-	-			0:03	-	-	-
1st Windward	24:23	24:20	9.7	3	11		24:12	24:11	9.6	5	12		1st Windward	23:43	23:41	9.6	2	12		24:37	24:34	9.7	3	11
1st Leeward	42:59	18:36	10.7	4	11		42:48	18:36	10.8	9	12		1st Leeward	42:24	18:41	10.7	8	12		43:07	18:30	10.7	2	11
2nd Windward	65:27	22:28	9.7	8	13		65:25	22:37	9.7	9	13		2nd Windward	64:40	22:16	9.6	8	13		66:11	23:04	9.6	10	13
Finish	85:06	19:39	11	3	12		84:48	19:23	11.3	8	13		Finish	84:17	19:37	11.1	8	13		86:20	20:09	10.9	5	12
Race 2													Race 2
MARK	Elapsed Time	Leg Time	Avg. Speed	Tacks/Gybes	Wind		Elapsed Time	Leg Time	Avg. Speed	Tacks/Gybes	Wind		MARK	Elapsed Time	Leg Time	Avg. Speed	Tacks/Gybes	Wind		Elapsed Time	Leg Time	Avg. Speed	Tacks/Gybes	Wind
Start	0:03	-	-	-			0:06	-	-	-			Start	0:15	-	-	-			0:10	-	-	-
1st Windward	25:01	24:58	9.6	7	12		25:13	25:07	9.4	7	14		1st Windward	26:11	25:56	9.5	11	14		26:16	26:06	9.6	7	12
1st Leeward	43:44	18:43	10.7	4	13		43:48	18:35	11	2	13		1st Leeward	44:08	17:57	11.3	5	13		44:48	18:32	10.9	4	13
2nd Windward	66:33	22:49	9.6	6	12		67:16	23:28	9.3	8	12		2nd Windward	67:30	23:22	9.3	9	12		67:41	22:53	9.7	6	12
Finish	86:44	20:11	10.7	4	12		88:12	20:56	10.5	5	11		Finish	87:59	20:29	10.8	5	11		87:24	19:43	11	4	12
Race 1													Race 1
MARK	Elapsed Time	Leg Time	Avg. Speed	Tacks/Gybes	Wind		Elapsed Time	Leg Time	Avg. Speed	Tacks/Gybes	Wind		MARK	Elapsed Time	Leg Time	Avg. Speed	Tacks/Gybes	Wind		Elapsed Time	Leg Time	Avg. Speed	Tacks/Gybes	Wind
Start	0:02	-	-	-			0:02	-	-	-			Start	0:03	-	-	-			0:02	-	-	-
1st Windward	23:57	23:55	10.3	5	11		24:43	24:41	9.7	5	7		1st Windward	25:35	25:32	9.6	5	7		25:00	24:58	10.2	5	11
1st Leeward	43:24	19:27	10.3	3	8		44:41	19:58	10.2	5	12		1st Leeward	44:48	19:13	10.8	4	12		44:05	19:05	10.4	3	8
2nd Windward	64:57	21:33	9.8	9	13		65:21	20:40	9.7	5	11		2nd Windward	66:42	21:54	9.8	2	11		65:27	21:22	9.8	9	13
Finish	83:52	18:55	11.3	6	8		85:12	19:51	10.5	4	5		Finish	87:31	20:49	10.7	3	5		84:35	19:08	11.1	6	8
	Emirates TNZ						Luna Rossa								Oracle BMW					Desafio Espanol
Averages		Leg Time	Avg. Speed	Tacks/Gybes	Wind			Leg Time	Avg. Speed	Tacks/Gybes	Wind		Averages		Leg Time	Avg. Speed	Tacks/Gybes	Wind			Leg Time	Avg. Speed	Tacks/Gybes	Wind
Upwind		24:34	9.52	11.17	11.33	Upwind		24:08	9.43	7.92	11.00		Upwind		24:27	9.43	8.25	11.00	Upwind		24:56	9.52	11.08	11.33
Downwind		20:00	10.56	3.50	12.90	Downwind		19:58	10.70	6.17	12.90		Downwind		20:01	10.81	6.33	12.90	Downwind		20:02	10.57	3.67	12.90
Race Time		89:11				Race Time		88:18					Race Time		89:03				Race Time		89:59
Adjusted		89:07				Adjusted		88:12					Adjusted		88:56				Adjusted		89:55
(minus start time)						(minus start time)							(minus start time)						(minus start time)
Other Stats:		Upwind									Downwind
(Avg.for all 4 boats)		Average boat speed (knots)						9.47			Average boat speed (knots)						10.66
		Average boat speed (meters/second)						4.87			Average boat speed (meters/second)						5.48
		Time for 1 boatlength									Time for 1 boatlength
		(i.e.25meters) in seconds						5.13			(i.e.25meters) in seconds						4.56
		Average leg length (direct nm)						3.30			Average leg length (direct nm)						3.30
Discussion
	The statistics show that in the 6 Semi Final races that data has been accumulated for:
Upwind	ETNZ's boatspeed was 0.09kn faster upwind than Luna Rossa, although L.R. reached the top mark 26 seconds earlier,
	(or about 5 boat lengths) however ETNZ had an average of 3.25 extra tacks per leg (42% more) and seemed to cover and attack more.
Downwind	ETNZ's boatspeed was 0.14kn slower downwind than Luna Rossa with L.R. completing an average of 2.2 (43%) more gybes per leg, however
	all 4 boats were only separated in avg. downwind leg time by 4 seconds (less than a boat length) possibly suggesting different pointing angles
	and more even VMG's (Velocity Made Good, i.e.- Speed toward the Mark)
	n.b.- The differences in average windspeed should be given less weight as the raw data is not accurate enough to
	be reliable. Readings were for averages over the course, not from individual boats.
	Also, being whole numbers,10.6 knots and 11.4 knots would both be shown as 11knots, increasing inaccuracy
	It may be more accurate to assume that as the races were sailed on the same courses with the second starting after a 10min delay
	that windspeeds were similar overall between races