Tuesdays - One Designs - Series 1

NHC1 is a progressive handicap. Each boat’s TCF starts from the fleet rating list and shifts after every race based on how its corrected time compared to the fleet average. Sail Scoring implements the SWNHC2015 algorithm (matches Sailwave NHC1 to 3 dp).

For each finisher: a fair TCF Q = O × P50 is computed (where O = 100 ÷ minutes elapsed and P50 = mean(TCF) ÷ mean(O)). The comparative score S = Q ÷ TCF measures over- or under-performance. Boats with S far from the fleet mean — outside μ(S) + 1.5·σ(S) or μ(S) − 1.0·σ(S), marked † — are classified extreme and blend more slowly.

The blend rate α depends on direction × extreme:

0.30

— non-extreme over-performer (TCF goes up).

0.15

— non-extreme under-performer.

0.15

— extreme over-performer.

0.075

— extreme under-performer.

Column meanings:

Q

— fair TCF for this boat in this race.

S

— comparative score Q ÷ TCF; † marks an extreme classification.

α

— the blend rate actually applied to this boat.

Z

— the blended provisional TCF before fleet-sum realignment.

Adjustment

— signed shift (New TCF − TCF, post-realignment).

Finally the whole fleet is realigned by Z51 = ΣTCF ÷ ΣZ (shown in the per-race fleet header) so the total fleet rating is preserved. New TCF = round(Z × Z51, 3) is the rating to apply in the next race. Non-finishers carry their TCF unchanged.