Play in a suit or in trump, made by leading small cards first whereas we holds one or several master cards. Example: I am declarer and I want to hunt the Petit with 21-20-19-15-12-9-7-6-2. I have the choice between drawing top trumps immediately (optimistic since only rewarded when the Petit is not more than third in a hand) or leading the 2 of trump, wishing that the Petit will not escape here (definitely better in probabilities). Another example: I am declarer, there is no more trump in play and I have the following suit to handle: R-D-C-2-1. I still have the choice between cashing from the top (I will make 5 tricks when the suit is distributed 3-3-3 in defense, but the chances of such a distribution is around 10%) or to duck the first round by playing the 1. As I probably have a loser in the suit (9 times out of 10), the ducking play is better to avoid valuable discards which would occur if I cash the top honors and found the suit distributed 4-3-2 (since 2 players will be able to discard on the fourth round). The ducking play concedes the loser while everyone follow the suit; it is thus a safety play which we make to protect ourself against bad break.