After a birthday party game of pin the tail on the donkey, my sister and I fell in love with blindfolds. We tried all sorts of games blindfolded. Baseball was impossible. Tag was very fun (and funny).
Our favorite was Follow The Leader. One blindfolded person would guide us through the woods, bumping into things (and the follower had to bump into the same trees). The follower would also warn if the leader got too close to, say, a steep drop or beehive.
We only realized how important that secondary role was after trying a quick game of “the blindfolded leading the blindfolded” which ended with an outbreak of poison ivy.
In bridge, our partner makes an opening lead with a blindfold on. They are using whatever information they have from the auction and their own hand. Once the lead is made, however, we do not need to keep following that plan if the dummy (or our own hand) suggests otherwise.
Let's look at a deal:
The auction:
| West | North | East | South |
|---|---|---|---|
| 1NT | |||
| Pass | 3NT | All Pass |
Partner leads the
4
| Vul:None Dlr: S |
 432 873 AJ10983 A |
|
| QJ105 A2 Q654 J94 |
You play the A and declarer follows with the 6. What next?
Our instinct should be to continue partner's suit. In general, as a defender, we don't want to play a bunch of new suits. That normally helps declarer. It also normally makes partner happy if you continue the suit they started. Is this case an exception?
Absolutely. Bridge rules are made to be broken with good reasons. Let's make sure we follow good procedure as a defender. Start by counting the points. We have 10 points, dummy has 9, and declarer about 16 (15-17). That means we can account for 35 points, give or take a point. That does leave partner room to have, say, the K and Q of hearts.
Another thing we analyze: the lead. Partner has led the 4. We should recognize that partner does not have five hearts, because with fourth-best leads, a fifth-best card would be available (a card lower than the 4). In this case, we can see the 3 and the 2 between our hand and dummy. That means that that we aren't going to take five quick tricks in hearts. Should we continue hearts anyway or maybe try to find the A with partner?
The last thing we look at is dummy. How will declarer use the dummy? Partner had no idea, but we can see a threatening diamond suit. We will be able to stop the diamonds from running once, but declarer could potentially return to dummy with the A to play diamonds once the diamond suit is set up.
We can stop this from happening and force declarer to find tricks in spades, hearts or clubs. We need to switch to a club at trick two. This is the "surefire" way. A continuation of hearts (or switch to spades) might work, but it will be hard to know until it's too late. After a club switch, declarer will try diamonds by playing the J from dummy(you duck) and winning the K in hand. When declarer leads another diamond and partner discards, declarer is going to give you a dirty look.
Look at the full deal:
| Vul:None Dlr: S |
432 873 AJ10983 A |
|
| 9876 J1054 2 KJ76 |
QJ105 A2 Q654 1098 |
|
| AK KQ96 K7 Q5432 |
Note that I like declarer's opening 1NT with this shape. South would have a big rebid problem if they open 1 and partner responds 1. With semi-balanced hands (6-3-2-2 and 5-4-2-2), you should think about your rebid before opening and you may open 1NT if you will be stuck otherwise.
Yes, partner could have made life easier by leading their best suit at trick one, but partner was blindfolded and we like to lead majors on this auction.
Advanced Easts might have guessed their partner's entire shape at trick one. We know that the 4 is a fourth best lead (from four) so partner has no five-card suits. Partner must also have at most one diamond (although declarer may, rarely, open 1NT with a singleton diamond). As a result, I'd picture partner 4-4-1-4 at trick one. Counting and thinking at trick one can make the rest of the play that much easier! You go from playing blindfolded, to playing like you can see all of the hands face up.