Opted for keeping the draw (to signify penalties) as it maintains the same difficulty level as the first couple of weeks. e.g. If the options are reduced to 2 you then have a 1 in 2 chance of backing the winner (ignoring the odds relating to the relevant strength of the teams involved for a second) Whereas with the draw kept in to signify a penalty shoot-out you stil have a 1 in 3 shot. If I went with your suggestion I reckon we would see more winners as the tournament progresses, entrenching the positions as they stand.
