WAC Open/Central Fall #2 — Analysis

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* This regatta is not official yet. Ratings marked * are from the last weekly update and have not absorbed this event; the performance columns use the results posted so far, and everything refreshes as scoring is finalised.

Performance rating answers one question for each skipper: holding every other skipper's rating fixed, which rating makes my actual race-by-race finishes least surprising? It is the maximum-likelihood rating under the same Plackett–Luce model that produces the power rankings (how accurate it is), with each opponent fixed at their rating from the last rated week before this event (2011-W41). Substitute skippers are scored only on the races they sailed, and races the boat did not finish (OCS, DNF and similar) are left out.

Percentile places a rating among the 1,605 ICSA skippers who were rated within the year before this event, so it reads as “better than X% of the skippers racing in this league right now”. The arrow shows where the sailor stood going in and where this performance would put them.

Surprise is how many bits more surprising the sailor's finishes were at their pre-event rating than at their performance rating (0 = exactly as expected). P(this good or better) simulates the regatta 3,000 times with the sailor at their pre-event rating against the actual fleet, and reports how often they would score this many points or fewer in the races they skippered. Races in one regatta are not independent, so each simulation also gives every skipper a good or bad regatta, form that drifts from race to race, and the speed of each boat the rotation puts them in (why). Low means an unusually good regatta, high means an unusually poor one. It deliberately ignores how rivals actually sailed, so it agrees with the performance rating rather than with the division finish, which also depends on everyone else's day. Ratings are shown on the rankings scale (model rating × 100). Only skippers are rated; crews are not part of the model.

  • n no rating before this event — the model's estimate from this week is used as the baseline.

Division A  12 boats · 10 races

Fin Skipper School Races Rating
before*
Perf.
rating
Δ Percentile
before → perf.
Surprise
(bits)
P(this good
or better)
Avg finish
actual / exp.
Rating
after*
1 Gerard Tonachel '13 Stevens Institute of Technology 10/10 257* 259 +2 85th → 85th 0.0 28% 2.7 / 3.4 256*
2 Nicholas Clemence '15 St. Mary's College of Maryland 10/10 275* 254 -21 88th → 84th 0.2 73% 3.8 / 3.2 277*
3 Samuel Bedinger '13 Washington College 10/10 145* 221 +76 61st → 78th 2.5 12% 3.9 / 5.4 170*
4 Samantha Gebb '14 Princeton University 10/10 154* 195 +41 63rd → 72nd 0.8 32% 4.4 / 5.3 157*
5 Connor Timmins '14 U. S. Naval Academy 10/10 220* 178 -42 78th → 69th 0.8 79% 5.1 / 4.1 222*
6 Paul Luisi '11 Monmouth University 10/10 50* 152 +102 39th → 63rd 4.4 8% 5.3 / 7.2 45*
7 Joan Boyle '14 Drexel University 10/10 78* 40 -38 46th → 37th 0.7 52% 6.7 / 6.7 76*
7 Victoria Miller '13 Christopher Newport University 10/10 84* 98 +14 47th → 50th 0.1 56% 6.7 / 6.6 86*
9 Autumn Hoover '12 Ocean County College 10/10 -9* -20 -11 25th → 21st 0.1 68% 9.0 / 8.3 -9*
10 Tim Gorzelnik '14 Rutgers University 10/10 -65* -46 +18 10th → 14th 0.1 44% 9.1 / 9.2 -34*
11 Charles Herlihy '14 Penn State University 10/10 -67n* -130 -64 10th → 3rd 1.7 77% 10.4 / 9.0 -67*
12 Tory Stires '14 University of Pennsylvania 10/10 -110n* -200 -90 4th → 1st 1.9 91% 11.5 / 9.6 -110*

Division B  12 boats · 10 races

Fin Skipper School Races Rating
before*
Perf.
rating
Δ Percentile
before → perf.
Surprise
(bits)
P(this good
or better)
Avg finish
actual / exp.
Rating
after*
1 Christian Geary '14 Stevens Institute of Technology 10/10 172* 201 +29 67th → 74th 0.4 13% 2.8 / 4.2 174*
2 Paul Stevens '14 Monmouth University 10/10 165* 177 +12 66th → 69th 0.1 19% 3.2 / 4.4 164*
3 John Marzulli '12 Princeton University 10/10 103* 170 +67 52nd → 67th 1.8 30% 4.6 / 5.6 132*
4 Jason Sinclair '13 Drexel University 10/10 21* 124 +102 32nd → 56th 4.6 4% 4.7 / 7.2 21*
5 Emma Ferris '15 U. S. Naval Academy 10/10 118n* 74 -45 55th → 45th 1.1 61% 5.6 / 5.3 118*
6 Brogan Savage '15 Washington College 7/10 62* 83 +21 42nd → 47th 0.1 82% 8.0 / 6.3 63*
6 Eleanor Conroy '15 Washington College 3/10 130* 191 +61 58th → 71st 0.5 22% 3.0 / 5.1 131*
7 Mary Buhl '14 Christopher Newport University 10/10 74* 92 +17 45th → 49th 0.1 65% 6.8 / 6.2 76*
8 Thad Bench '15 St. Mary's College of Maryland 6/10 53n* -20 -73 40th → 21st 0.8 91% 10.0 / 6.6 53*
8 Allison Shane '15 St. Mary's College of Maryland 4/10 154* 209 +55 63rd → 76th 0.5 24% 3.0 / 4.6 154*
9 Kyle Donnelly '14 Ocean County College 10/10 11* -25 -36 29th → 20th 0.6 74% 8.5 / 7.4 10*
10 Welf Ludwig '12 Rutgers University 6/10 -150* -277 -127 1st → 1st 1.6 73% 11.0 / 10.1 -156*
10 Kathrine Bianchini '12 Rutgers University 4/10 -17n* -7 +10 22nd → 25th 0.0 63% 9.0 / 7.9 -17*
11 Eliza Crawford '14 Penn State University 10/10 -66* -146 -80 10th → 2nd 2.1 84% 10.3 / 8.9 -66*
12 Matthias Chia '15 University of Pennsylvania 10/10 -12n* -50 -38 23rd → 13th 0.5 91% 10.7 / 7.8 -12*

From the notes

Short write-ups of what the ratings and results show, with the numbers and how they were computed.

All notes →