06-01-2016, 08:50 PM
This will have 4, possibly 5 parts.
First: what am I talking about? You sit West; South is declarer. South cashes some number of aces, then exits with a low trump. You have a trump ace. Beginners are taught to win the ace to be able to cash aces. This minimizes the risk of losing your aces, and can be helpful in finding a path to your partner. So it's often sound practice. However, that's not always the case. There are times you don't want to. These can be grouped by *which hand* is the focus: your hand, dummy, your partner, or declarer.
I'll start with when your hand suggests the duck. There are 3 main considerations:
1. You have good trump length with secondary strength...that means 10s.
2. You don't have side aces at unacceptable risk.
3. You have side-suit tricks ready.
Good trump length with secondary strength means at least ATKJJJ. Your ace bolsters your tens; your length can cause problems. Some cases:
... minimum. This won't be enough, most of the time, for you to duck based on your hand alone. Here, you want those side-suit tricks. A full hand might be:
With clubs trumps, declarer cashes the missing before exiting. If you have spade or heart aces, they're not at high risk. Your diamond tricks are all good to go. *IF* things can work out, you MAY take 2 club tricks and 5 diamond tricks. Is this dreaming? Probably, but your hand says it's not all that risky.
... OK, now I want not 2 but 3 tricks out of this suit. This isn't a dream; it's quite possible. A big plus for this duck: dummy melded aces.
... I'm not ducking...which would be the ... based only on my hand. I might be ducking to reach my partner, but that's for later. I *might* well choose to try a finesse by playing the ... if it wins, I have 3 tricks. I'm more likely to do this with AATx or AATxx.
... the is part duck, and part deep finesse. It *might* win...not that far-fetched. The other very sweet scenario is if it goes 
, , , to partner's . HEAVEN! But playing the will ensure 4 tricks unless dummy wins with a .
I've only shown 6 card suits. Throw in a 7th, and the duck stands to gain even more. Your trump length often matches declarer's, so you're contesting for trump control. You're managing trump as if you were declarer. With ATTKKJJ, you don't want to start with *your* ace...so don't do it here. Now, you may need to rise and win based on your hand, or based on your partner's hand, but you need to find a good reason to do so.
Also, I've never made these runs. Changing a jack to a queen hardly matters from a power perspective...but the run, versus the non-run, *greatly* matters from the standpoint of concealing your intentions. When you have not disclosed that trump ace...the run, or melding aces...declarer may think at some point, OK, let's run trumps out. Your holding will be an unpleasant surprise. When you duck with the run, declarer is warned.
First: what am I talking about? You sit West; South is declarer. South cashes some number of aces, then exits with a low trump. You have a trump ace. Beginners are taught to win the ace to be able to cash aces. This minimizes the risk of losing your aces, and can be helpful in finding a path to your partner. So it's often sound practice. However, that's not always the case. There are times you don't want to. These can be grouped by *which hand* is the focus: your hand, dummy, your partner, or declarer.
I'll start with when your hand suggests the duck. There are 3 main considerations:
1. You have good trump length with secondary strength...that means 10s.
2. You don't have side aces at unacceptable risk.
3. You have side-suit tricks ready.
Good trump length with secondary strength means at least ATKJJJ. Your ace bolsters your tens; your length can cause problems. Some cases:
... minimum. This won't be enough, most of the time, for you to duck based on your hand alone. Here, you want those side-suit tricks. A full hand might be: With clubs trumps, declarer cashes the missing
before exiting. If you have spade or heart aces, they're not at high risk. Your diamond tricks are all good to go. *IF* things can work out, you MAY take 2 club tricks and 5 diamond tricks. Is this dreaming? Probably, but your hand says it's not all that risky. ... OK, now I want not 2 but 3 tricks out of this suit. This isn't a dream; it's quite possible. A big plus for this duck: dummy melded aces. ... I'm not ducking...which would be the ... based only on my hand. I might be ducking to reach my partner, but that's for later. I *might* well choose to try a finesse by playing the ... if it wins, I have 3 tricks. I'm more likely to do this with AATx or AATxx. ... the is part duck, and part deep finesse. It *might* win...not that far-fetched. The other very sweet scenario is if it goes , , , to partner's . HEAVEN! But playing the will ensure 4 tricks unless dummy wins with a .I've only shown 6 card suits. Throw in a 7th, and the duck stands to gain even more. Your trump length often matches declarer's, so you're contesting for trump control. You're managing trump as if you were declarer. With ATTKKJJ, you don't want to start with *your* ace...so don't do it here. Now, you may need to rise and win based on your hand, or based on your partner's hand, but you need to find a good reason to do so.
Also, I've never made these runs. Changing a jack to a queen hardly matters from a power perspective...but the run, versus the non-run, *greatly* matters from the standpoint of concealing your intentions. When you have not disclosed that trump ace...the run, or melding aces...declarer may think at some point, OK, let's run trumps out. Your holding will be an unpleasant surprise. When you duck with the run, declarer is warned.
