I've had a couple of dozen tries and have yet to win a game
Is it winneable?
EDIT: Found the solution...the team with the first move would leave the opponent with 20 flags the first turn. No matter how many flags were then taken by the opponent, the team in control could then leave the opponent with 16 flags and then 12 and then 8 and lastly 4. Left with only four flags and the requirement to take at least one, but not more than three, means that you MUST put the opponent within range of winning, but cannot win yourself. It is a 'master-move.'