We could try double letters ( any position in word) - no idea how doable that is for the entire alphabet I ill start with Aardvark, if you get stuck default to consecutive letters e.g. rABid.
Good idea but how about just doing consecutive letters all the way through eg
I think that should be in a new game topic though to avoid confusion. Maybe a good name for it would be "Consecutive Streak".
Having said that there are a number of letters that dont go together at all so a lot of cases would need to be missed out.