World
Game
Of
Sprouts
Association

# Early Sprouts Strategy Document

Rummaging around with Google, I found an early, incisive discussion of sprouts strategy, in the rec.games.abstract newsgroup. Note the date!

dave boll Nov 16 1992, 6:26 am

Newsgroups: rec.games.abstract

Re: Sprouts

Someone posted an article requesting strategy for the topological game sprouts. Here's *my* strategy - it may not be all that great, but it's at least maybe sort of a bit on the right track. Say you're playing sprouts with 7 dots and you're moving first. Well, you know that a sprouts game can last at most 3n-1 moves (n=number of starting dots), or 20 moves in this case. Since you're moving first, you want the game to last an odd number of moves. So, you make a table of numbers of possible moves for the game: 20, 19, 18, 17, 16, etc. (I believe the minimum # of moves in sprouts is 2n or 2n+1). Now, each time a new 'stranded dot' is created, cross off the highest number on the list. New stranded dots are created every time you chop the playing field up into 2 areas that are each guarenteed to contain a dot that is not totally used up by the game's end.

Try to get to the part of the game where no more dots can be stranded with an odd number at the head of the list.

Beware of creating semi-stranded dots that give your opponent the option of actually stranding a dot or not (Ex: picture a circle with 4 dots on the perimeter, and with other stuff outside the circle.) There are cases when you'd want to do this, but be careful.

This isn't so much a strategy as it is a way of deciding what type of move to make: a non-stranded-dot move (ex: connect 2 points), a stranded dot move (ex: encircle an open point), or a semi-stranded dot move (ex: connect a point to itself, now your opponent has the option of connecting the 2 dots on the inside or outside of the circle).

Perhaps this note is the earliest published description of the strategical concepts of survivors and switches. The note also confers very nice names upon these concepts ("stranded dots" and "semi-stranded dots", respectively.)