[straube]

Partner proposed using the Obvious Switch (Granovetter wrote about it) for defense, but I remember Rodwell saying that attitude signals should be about the suit being lead and not about some other. What are the experts doing now?

[dburn]

To the best of my knowledge, they are playing as Rodwell suggests (and as they have been playing for decades). That is: if they want partner to continue the suit led, they encourage it; if they want partner not to continue the suit led, they discourage it and hope that partner can work out what they want him to do instead.

They do a couple of other things also, but these may safely be dismissed as idiosyncrasies. A problem I faced only the day before yesterday concerned this hand:

♠J103 ♥J10765 ♦K ♣K1084

You pass at unfavourable vulnerability, LHO passes, partner opens 1♥ (in principle five, but may be four in third seat), RHO doubles. What call do you make? (2NT sound raise; any number of hearts pre-emptive raise; 3♣ clubs and hearts; no other artificial calls available).

You may wonder what this has to do with the question in the OP, but all will become clear. In the meantime, I thought it was an interesting bidding problem.

[bluecalm]

I think I would bid 2NT.

[jjbrr]

lol i read the OP and then the third message, but the second message was tl;dr. "I think I would bid 2NT" seemed like a pretty good response about Obvious Shift.


Anyway, I prefer attitude in the suit led.

[Lobowolf]

I wouldn't look at it as a pure dichotomy, though; part of answering the question "Do I want my partner to continue the suit led?" involves an awareness of what partner will likely do if he DOESN'T continue. The Granovetters took the principle to the nth degree, and created a scheme of rules addressing situations in which the "obvious shift" isn't so obvious, but the basic obvious shift principle preceded the publication of A Switch in Time.

[Phil]

dburn, on Apr 25 2010, 08:04 PM, said:

♠J103 ♥J10765 ♦K ♣K1084

You pass at unfavourable vulnerability, LHO passes, partner opens 1♥ (in principle five, but may be four in third seat), RHO doubles. What call do you make? (2NT sound raise; any number of hearts pre-emptive raise; 3♣ clubs and hearts; no other artificial calls available).

I can't improvise with 3N and expect partner not to understand? If not, then 4♥.

I didn't think Meckwell used OS by the book, but they did have some similar method but I do not know what it is specifically.

I'm guessing Dburn is having us lead the ♥J against 4♠ and we have to work out the switch based on pard's card.

[mike777]

so we are suggested

not OS 100% by the book but very close for starters?

I am lucky if i can convince exp pards to play 50% sigh.......they know 100% of whatever....I dont.....

typical is that at trick one...........often....suit pref not att...sigh........I try.....

[awm]

I've played obvious shift in several partnerships and been very happy with the method.

I think it's fairly common at the expert level to encourage a suit when you don't really want partner to shift away from an honor in some side suit; in other words, even though you have nothing much in the suit lead, you think continuing it is a better defensive strategy than the alternatives.

Perhaps the point is that some hands call for a passive defense, and encouraging the opening lead is more likely to help partner find such defense. Discouraging thus says not only "I don't want you to continue the suit you lead" but also "please play something else at your first opportunity."

With that said, not many expert pairs have a formal set of agreements about which suit is the "obvious shift" that a discouraging signal requests partner to switch to. However, usually this suit is sufficiently "obvious" that it's not much of an issue.

[Codo]

Experts do not need OS, they can work it out for themselves when to signal for continuation and when for a shift.

But for lesser players OS is a great tool. Simply because it make you think like an expert on any given defensive hand.
You do not give a card for the lead suit in isolation, but you are forced to look at the complete hand.

This should be done always, but millions of players fail to do so every single day.
So OS will improve the defence of most players dramatically. Not because it is a superior system (it is not) but because it teaches to think about the complete hand.

You do already? Always? No need to switch in time.

[Free]

One of my partners insisted to play OS. I've been playing OS with him for more than a year now, and I haven't encountered any problems so far. Instead of thinking like an expert and failing miserably, we prefer a strict rule which works in almost every situation. In fact, we've had some great defenses, even when we ask for a switch which is not the OS (throwing an honour card under partner's Ace or dummy's higher honour)! Without the clear signal, it would've been too risky to switch to that suit.

[gwnn]

I would bid 4♥. I do not have much to contribute to the issue of OS since none of my partners have proposed it to me and neither have I to them, but I felt the need to clarify that it's not just bluecalm who is interested in what happens next.

[Codo]

2 Nt and what happens next?

[bluecalm]

Btw, for people who have some experience actually playing obvious switch (I don't have any, I've skimmed through Granovetter's book): can you please give more agreements you have/had ?
Do you play obvious switch in every situation ?
If not what are the situations which you play attitude in lead suit (or count) ?

The method I prefer playing is simple attituide and if that's not relevant then count and if that's not relevant (AK sec in dummy, 3 stoppers etc) then suit preference but then we give suit preference in trumps and other suits played by declarer if they don't require count (partner holding up with an honour etc.). I would like to hear more about relative merits of those methods.

[pooltuna]

dburn, on Apr 25 2010, 08:04 PM, said:

To the best of my knowledge, they are playing as Rodwell suggests (and as they have been playing for decades). That is: if they want partner to continue the suit led, they encourage it; if they want partner not to continue the suit led, they discourage it and hope that partner can work out what they want him to do instead.

They do a couple of other things also, but these may safely be dismissed as idiosyncrasies. A problem I faced only the day before yesterday concerned this hand:

♠J103 ♥J10765 ♦K ♣K1084

You pass at unfavourable vulnerability, LHO passes, partner opens 1♥ (in principle five, but may be four in third seat), RHO doubles. What call do you make? (2NT sound raise; any number of hearts pre-emptive raise; 3♣ clubs and hearts; no other artificial calls available).

You may wonder what this has to do with the question in the OP, but all will become clear. In the meantime, I thought it was an interesting bidding problem.

I would try 4♥

[Phil]

I should have mentioned that I have played it for about 10 years in one partnership. He loves it; I like it.

It gives an immense amount of information away to declarer, which is the main drawback. But as Free states, you can practically defend double dummy in a lot of cases.

[mikeh]

I played OS in what has been my most successful partnership until we stopped playing in 2000. It made defence so easy: going back to normal defence, even with expert partners, was like someone turning out the lights in a room at dusk: I could still see, but nothing was as clear as it had been.

When we first started using it, and getting good results, we went overboard, like many a convert. We then found that expert declarers were picking us apart, because we were sending out far too many accurate signals.

So we limited our OS....always on the opening lead, and never after about trick 4 or 5....and the extent to which we used OS at tricks 2-5 depended on what was going on....generally, if OS applied (ie no other signal took priority) we did OS for the first 3-4 tricks. And suit preference in trump throughout.

Edit: re free's modest remark that he likes OS because it is strict rules and one doesn't have to think like an expert: OS is not a substitute for judgement: it is a method that allows the defenders to exchange more information than can most, and to then apply their judgement with the benefit of the information. It can turn an average defender into an apparent expert defender, and make an expert seem world class. The key is that signaller uses judgement to decide what signal to give and partner uses judgement to decide what to do with the information conveyed.

[straube]

The response so far is more positive than I would have thought. I wonder what Fred Gitelman thinks of it (hint).

[bluecalm]

Quote

So we limited our OS....always on the opening lead, and never after about trick 4 or 5....and the extent to which we used OS at tricks 2-5 depended on what was going on....generally, if OS applied (ie no other signal took priority) we did OS for the first 3-4 tricks. And suit preference in trump throughout.

How signalling OS works after you already gave one such signal ?
So let's say on opening leads you played low to show that you can tolerate obvious switch, which Axx suit in dummy.
Declarer won 1st trick and played other suit in which you have another chance to signal. You play low. Does it mean you have KQ/KJ/QJ now or something else about your hand ?

[Phil]

If you play OS by the book, subsequent cards after T1 by both defenders are meant to convey suit preference. This is primarily valuable by opening leader.

I also think Smith Echo is very important by responder when playing OS.

There is judgment involved. When the board has KJT and that's the OS, don't automatically signal encouragement with the Q, even though that's conventionally what you're supposed to do.

[kgr]

bluecalm, on Apr 26 2010, 05:32 PM, said:

Do you play obvious switch in every situation ?
If not what are the situations which you play attitude in lead suit (or count) ?

We play OS in every situation (Also when trump is lead, or with a singleton in dummy).
The next signal(s) when declarer leads are Lavinthal until we told enough.
(When it probably costs a trick if partner continues the opening suit and we don't have the OS suit then we can lie about the OS).