15. Thiruvottiyur

Dravida Munnetra Kazhagam held the seat; the winning margin narrowed from 22.5% to 16.8%.

• Won on a lower shareIts own vote share fell 7.5% — it held because the rest of the vote was more divided.
• New challengerNCO (NCO) finished second with 36.9% — it did not contest here in 1967.
• Vote fragmentedThe top two took only 90.7% between them, down from 100.0% — the field split more ways.

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