← All ORC handicap examples

ORC — all-purpose time-on-distance (APHD) over a recorded course length

ORC Rating Systems 403.2: CT = ET − (ToD − ToD of the scratch boat) × distance. The scratch boat is the fleet's lowest allowance; its corrected time equals its elapsed time. Distance is recorded to 0.01 NM (401.3).

APHD values from the boats' real 2026 IRL ORC certificates:
  Mojo (J-80)           APHD 594.7 s/NM — the scratch boat
  Impetuous (Corby 25)  APHD 623.0 s/NM

A 3.24 NM course (the length of AL 2025 race 2), start 15:15:00.
Impetuous is owed (623.0 − 594.7) × 3.24 = 28.3 × 3.24 = 91.692 s:
  Mojo:      finish 15:50:51  ET = 2151 s  CT = 2151 − 0      = 2151    → 2nd
  Impetuous: finish 15:51:49  ET = 2209 s  CT = 2209 − 91.692 = 2117.31 → 2117 → 1st

Impetuous crosses nearly a minute behind and wins on corrected time.
Cross-checked against the ZW manual's worked ToD example for the
rounding convention (half-up to whole seconds).

Race arithmetic

Series standings