Letter on position 1 (b) changed: 13 words cark dark hark jark kark lark mark nark park rark sark wark yark Letter on position 2 (a) changed: 4 words berk birk bork burk Letter on position 3 (r) changed: 5 words back balk bank bask bauk Letter on position 4 (k) changed: 8 words barb bard bare barf barm barn barp bars