18. Bishalgarh

Indian National Congress held the seat; the winning margin narrowed from 13.3% to 1.6%.

• Won on a lower shareIts own vote share fell 23.3% — it held because the rest of the vote was more divided.
• New challengerCommunist Party of India (Marxist) (CPM) finished second with 30.7% — it did not contest here in 1967.
• Vote fragmentedThe top two took only 63.0% between them, down from 97.9% — the field split more ways.

Written from the constituency figures by a fixed set of rules — no language model.