The route reaches the final bridge PROP, then changes letter 2 to reach POOP. Its 8 moves match the dictionary distance calculated from the target.
Compare the first move
ARCS has 5 accepted one-letter neighbors in this vocabulary. 2 can begin a shortest route: ARKS, ARMS. Each leaves exactly 7 moves to POOP.
Some longer openings are ARCH (10 total moves), ARTS (9 total moves), ORCS (10 total moves). These counts include the first move from ARCS.
Similarity can be misleading
ARCS → ARKS, ARKS → IRKS, IRKS → IRIS, IRIS → BRIS do not reduce the number of letters that differ from POOP, but still belong to a minimum-move route. Reachable word connections matter more than matching letters immediately.
If a word is rejected
Enter the last accepted word in the solver, exclude the rejected word, and recalculate. A shorter dictionary can require more moves. Read the strategy guide for a worked detour example.