Source: Leading unsupported aces against a suit contract – part 1, Bulletin March 2006 ACBL
In [ilink url=”http://csbnews.org/new/?p=44602″]Part I[/ilink] we examined leading aces against non-slam suit contracts. I am on record, along with just about every good player that I know as being strongly against ace banging. One of the hardest thing to prove is that leading unsupported aces is a terrible way to make a living. The reason it is hard to prove is that it is wrong two-thirds of the time, makes no difference about 10% of the time, and is a good lead about 25% of the time. Players tend to remember their successes and to forget their failures.
Few things are more annoying than to lead some other suit and watch declarer get rid of two losers and then later find out that if you had led your ace, you would have taken two more tricks. This can happen.
What is more likely to happen (trust me on this) is that banging down your ace will give up one or more tricks later in the play. Since leading an ace can be effective some of the time, let’s see when that might be. (Remember, we’re not talking about slams.)
Here is an assortment of hands where you are on lead. You are South in each of them. Specifically do you lead your ace or not/ If not, what do you lead? For each question, decide what your reasons are. Reasons count for more than guesses.
1) No one vulnerable. North deals
10 8 7 5 2 
62 
9 6 
A Q 6 3
| West | North | East | South |
| Pass | 1 |
Pass | |
| 2 |
2NT | 4 |
5 |
| Pass | Pass | 5 |
The End |
2) No one vulnerable. West deals
A 8 7 3 8 3 9 8 J 10 9 8 4
| West | North | East | South |
| 1 |
3 |
4 |
4 |
| 4NT | Pass | 5* |
Pass |
| 5 |
The End | ||
* Zero o Three keycards
3) North-South vulnerable. North deals
A 2 K J 8 7 3 K 8 2 J 7 4
| West | North | East | South |
| Pass | 1 |
1 |
|
| Pass | 1 |
2 |
Pass |
| 2 |
The End | ||
4) No one vulnerable. North deals
8 7 3 Q J 3 A J 10 8 7 6 3
| West | North | East | South |
| 1 |
2 |
3 |
|
| 4 |
The End | ||
5) No one vulnerable. South deals
Q 7 A Q J 7 5 K Q J 6 Q 4
| West | North | East | South |
| 1 |
|||
| Dbl | 3* |
4 |
The End |
* at least 4 hearts, 5-7 points
Answers
1. Lead the A. Your side has at least nine clubs. It is unlikely that East has the doubleton K. North is likely to have the K. Also there is a danger in the alternative lead, diamond. If East can win the diamond lead, he might be able to discard some club losers on the spades. This is a more complex hand than most. Still, I lean toward the A with a fair feeling of comfort.
2. Lead the A. This time your side has so many spades that you know one or both of the opponents has a singleton. Your ace lead could set up their king (unlikely), but if it does your side did not have two spade tricks in any event. One small detail is that if the A holds, you may have a hint from dummy as to what to do next.
3. Lead the A. It is not that this lead stands out. In large part, the A is right for three reasons, none individually significant. But in total they’re enough to sway you to leading the ace: nothing else looks good; North bid them; you may get a ruff.
4. Lead the A. Leading a singleton ace is often a good idea. The situation here suggests it is a good lead because after taking the first trick, you should be able to get to partner’s hand for a ruf. You suspect that North’s entry is in hearts but the sight of the dummy may tell you where that entry is.
5. Under no circumstances consider leading the A. If you are looking at an unsupported ace, always think seriously about other leads. If you lead the A, you may get a second heart trick. But you may not. That lead will never set up new tricks for you. The K may set up one or two tricks for you and that makes it the right lead by a mile. This is standard situation: should you lead an ace or try to set up tricks in another suit?
Go for setting up the side suit tricks. Remember that if you keep the A, you do not automatically give up on getting heart tricks. And if East has the K, leading diamonds may allow you to get two heart tricks instead of one (which is probably what would happen if you thumped your ace 0n the table at trick one).