RRS A8.1 lists each boat's race scores best-to-worst "No excluded scores shall be used" — discarded races are left out. Here that exclusion is decisive. Alice and Bob both net 5 with one discard. Their non-discarded scores are identical ([2, 3] each), so A8.1 cannot separate them — even though Alice's discarded race is a DNC (5) and Bob's is a 4th (4). A8.2 then counts back from the last race: race 3 has Alice 3rd and Bob 4th, so Alice ranks ahead.
This is the case the pre-2025 place-count tie-break got wrong: it counted Bob's discarded 4th place (a back-of-fleet score) as if it helped him and ranked Bob ahead. A8.1/A8.2 rank Alice ahead.
Scoring configuration: 1 discard from race 3. DNF/OCS scoring: A5.2 (series entries).
4 boats, N+1 = 5 (DNC). One discard (worst score dropped).
Alice: DNC, 2nd, 3rd → {5,2,3} discard 5 → net 5, kept best-to-worst [2, 3]
Bob: 2nd, 3rd, 4th → {2,3,4} discard 4 → net 5, kept best-to-worst [2, 3]
Carol: 1st, 1st, 1st → {1,1,1} discard 1 → net 2 (wins outright)
David: DNC, 4th, 2nd → {5,4,2} discard 5 → net 6 (last)
Alice and Bob tie at net 5.
A8.1 — kept scores [2,3] vs [2,3] → identical, cannot separate
A8.2 — last race (race 3): Alice=3, Bob=4 → Alice wins
Alice and David DNC; Carol 1st, Bob 2nd