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J/88 performance analysis

Exile: J/88 performance

Tack speed, turn duration, acceleration, and recovery across six sessions.

Graham Eger · J/88 crew

June 2021–September 2022 · GPS archive July 2020 Chicago · Lake Michigan

All sessions · 83 analyzed tacks · 74 unavailable

Instrument performance

Speed through the turn

83 analyzed tacks74 censored / not analyzed17 s median turn duration16 s median recovery

Aligned tack speed

83 turns · BSP kt · median / IQR
02.95.88.8-2920.369.7119BSP · kttime · s
Each turn contributes at most one boat speed (BSP) value per second. Gaps of up to 3 seconds are interpolated. Faint lines show individual turns.

Selected tack

4.25.26.17.1-300306090120BSP · kttime · s
Entry 6.1 · low 4.2

Wind angle through turn

TWA °
-42.6-5.731.268.2-300306090120TWA · ° unwrappedtime · s
Recorded true wind angle (TWA), unwrapped across ±180° to keep the trace continuous. The cursor shows the original signed angle. The dashed line marks the detected turn at 0 seconds.

Turn duration

83 tacks · s
02549counts4.877.1149.5
Hover or focus a bar to inspect its interval and count.
Observed distribution; median 17 s.

Recovery

83 tacks · s
02754counts7.657.2106.8
Hover or focus a bar to inspect its interval and count.
Observed distribution; median 16 s.

Acceleration

83 tacks · s
02754counts4.853.9102.9
Hover or focus a bar to inspect its interval and count.
Observed distribution; median 12.7 s.

Recovery by session

median seconds · analyzed tacks
011.623.2median · s123456
Hover or focus a session to inspect its median and sample count.
1. 2021-06-05: 16 s (n=28) · 2. 2021-06-06: 23.2 s (n=13) · 3. 2021-06-13: 16.4 s (n=3) · 4. Verve · Aug 13–15, 2021: 16.4 s (n=29) · 5. Sheldon Clark · Sep 18, 2021: 14.7 s (n=9) · 6. Sep 18, 2022: 15.1 s (n=1)

Entry speed versus recovery

83 analyzed tacks · BSP kt / recovery s
7.640.773.7106.83.94.95.86.7recovery · sentry BSP · ktTurn: 6.1 kt, 14.5 sTurn: 6 kt, 10.7 sTurn: 6.1 kt, 14.1 sTurn: 6.4 kt, 8.9 sTurn: 6.7 kt, 46.6 sTurn: 6.1 kt, 11.1 sTurn: 6.4 kt, 16 sTurn: 6.1 kt, 25.2 sTurn: 6.3 kt, 10.8 sTurn: 6.1 kt, 10.5 sTurn: 6.2 kt, 23.6 sTurn: 6.5 kt, 25 sTurn: 6.4 kt, 18.3 sTurn: 6.3 kt, 17 sTurn: 6.2 kt, 7.6 sTurn: 6.3 kt, 15.7 sTurn: 6.3 kt, 22.8 sTurn: 5 kt, 12 sTurn: 6.2 kt, 13.8 sTurn: 6.2 kt, 21.6 sTurn: 6.2 kt, 25.1 sTurn: 6.3 kt, 18.9 sTurn: 6.2 kt, 10.7 sTurn: 6.1 kt, 54.1 sTurn: 6.7 kt, 51.4 sTurn: 5.9 kt, 16 sTurn: 6.4 kt, 38.1 sTurn: 6.2 kt, 14.9 sTurn: 5.1 kt, 23.2 sTurn: 5.1 kt, 23.7 sTurn: 4.9 kt, 9.3 sTurn: 5.2 kt, 66.6 sTurn: 5.3 kt, 14.3 sTurn: 4.9 kt, 14.9 sTurn: 5.5 kt, 57.7 sTurn: 4.9 kt, 8.6 sTurn: 5.7 kt, 106.8 sTurn: 5.3 kt, 11.7 sTurn: 5.5 kt, 37 sTurn: 4.4 kt, 30.1 sTurn: 5.5 kt, 10.8 sTurn: 5.6 kt, 9.8 sTurn: 5.6 kt, 22 sTurn: 3.9 kt, 16.4 sTurn: 5.3 kt, 21.7 sTurn: 6 kt, 16.3 sTurn: 6.3 kt, 24.4 sTurn: 5.9 kt, 8.7 sTurn: 5.9 kt, 17.6 sTurn: 5.7 kt, 9.2 sTurn: 5.7 kt, 11.8 sTurn: 6.3 kt, 24.5 sTurn: 5.6 kt, 15.2 sTurn: 4.4 kt, 9.8 sTurn: 6.1 kt, 13.9 sTurn: 6.3 kt, 15.9 sTurn: 5.3 kt, 87.3 sTurn: 5.9 kt, 19.3 sTurn: 5.1 kt, 8 sTurn: 5.8 kt, 16.7 sTurn: 4.8 kt, 11.5 sTurn: 4.6 kt, 7.7 sTurn: 5.7 kt, 38.9 sTurn: 5.3 kt, 24 sTurn: 5.1 kt, 16.4 sTurn: 5.4 kt, 64.5 sTurn: 5.3 kt, 11.3 sTurn: 5.9 kt, 23.2 sTurn: 5.3 kt, 9.3 sTurn: 4.9 kt, 17.4 sTurn: 5.2 kt, 33.2 sTurn: 5.6 kt, 9.6 sTurn: 4.8 kt, 72.5 sTurn: 5.2 kt, 13.5 sTurn: 4.9 kt, 14.7 sTurn: 5.7 kt, 12.3 sTurn: 5.9 kt, 17.2 sTurn: 6.1 kt, 29.4 sTurn: 5.6 kt, 12.9 sTurn: 5.9 kt, 15.1 sTurn: 5.9 kt, 14.3 sTurn: 6.1 kt, 17.3 sTurn: 5 kt, 15.1 s
Hover or focus a point to inspect entry speed and recovery.
Each point represents an analyzed tack. Recovery is the time taken to return to the speed threshold based on entry speed.

Distance lost through the turn

RankSession / turnEntry / low BSPTurn / accelerationLossRecoveryStatus / reason
1Verve · Aug 13–15, 2021 · 8/14/20215.3 kt / 1.6 kt110.4 s / 57.5 s44.4 m87.3 sAnalyzed
2Verve · Aug 13–15, 2021 · 8/13/20215.3 kt / 2 kt149.5 s / 17.6 s34.4 m21.7 sAnalyzed
32021-06-06 · 6/6/20215.5 kt / 3.7 kt16.4 s / 30.8 s23 m37 sAnalyzed
42021-06-06 · 6/6/20215.5 kt / 3.4 kt52.5 s / 51.5 s21.4 m57.7 sAnalyzed
5Verve · Aug 13–15, 2021 · 8/14/20215.4 kt / 3.4 kt78.6 s / 62.8 s20.6 m64.5 sAnalyzed
62021-06-05 · 6/5/20216.3 kt / 3.5 kt82.9 s / 17.9 s20.2 m22.8 sAnalyzed
72021-06-05 · 6/5/20216.2 kt / 4.2 kt16.8 s / 21.9 s19.2 m25.1 sAnalyzed
8Verve · Aug 13–15, 2021 · 8/13/20216.3 kt / 4 kt4.9 s / 22.6 s17.6 m24.4 sAnalyzed
92021-06-06 · 6/6/20214.4 kt / 3 kt30.7 s / 29.8 s16.6 m30.1 sAnalyzed
10Verve · Aug 13–15, 2021 · 8/13/20216.3 kt / 4 kt6.1 s / 23.5 s16.3 m24.5 sAnalyzed
112021-06-06 · 6/6/20215.7 kt / 3.9 kt5.9 s / 102.9 s15 m106.8 sAnalyzed
12Sheldon Clark · Sep 18, 2021 · 9/18/20214.9 kt / 2.9 kt24 s / 13 s15 m14.7 sAnalyzed
—Verve · Aug 13–15, 2021 · 8/13/20216.4 kt / 1.2 kt— / —60.1 m—Not analyzed: no held pre-turn TWA-stable departure observed; BSP recovery to threshold censored or missing before observation boundary
—Verve · Aug 13–15, 2021 · 8/13/20215.9 kt / 1.8 kt— / 44.3 s52.9 m73.1 sNot analyzed: no held pre-turn TWA-stable departure observed
—Sheldon Clark · Sep 18, 2021 · 9/18/20216 kt / 2.7 kt— / 37.7 s52 m51.5 sNot analyzed: no held pre-turn TWA-stable departure observed
—Sheldon Clark · Sep 18, 2021 · 9/18/20217 kt / 3.4 kt— / 38.5 s49.1 m40.2 sNot analyzed: no held pre-turn TWA-stable departure observed; TWA settlement censored or missing within observation limit
Entry hold compares recorded distance with the distance traveled at a constant entry speed. Each metric uses its available measurements. Missing values include the reason they could not be calculated.

Recorded sailing

Course and track

Loading track…

Observation coverage

Recording coverage

10admitted records
6sailing sessions
59course candidates
11four-leg patterns
Each row represents one sailing record. The August 13 session spans August 13–15. Candidates include incomplete course patterns and do not establish an official race count.
Observed dateRowsContinuous segmentsLegsCandidatesFour-leg patternsInferred finishes
2021-06-0523,675102181500
2021-06-0621,67846161010
2021-06-1314,2015210700
2021-08-1362,7091421960
2021-09-1822,370120740
2022-09-1810,92013100

Repeated records count once.

Detection sensitivity

The agreement threshold is the fraction of observations required to identify a sailing phase. These results cover the September 18, 2022 reference session only.
Agreement thresholdRetained legsComplete patternsInferred finishes
55%300
60%300
70%300

Sources

YachtScoring event metadataFirst championship raceLast championship raceChampionship standings