Letter on position 1 (b) changed: 16 words cats eats fats gats hats kats lats mats nats oats pats qats rats tats vats wats Letter on position 2 (a) changed: 4 words bets bits bots buts Letter on position 3 (t) changed: 11 words baas bacs bads bags bals bams bans baps bars bass bays Letter on position 4 (s) changed: 3 words bate bath batt