[FrancesHinden]

Scoring: Total Points

3♥ P P x
P 4♠ all pass

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April/May is our busiest time of year bridgewise. This weeked you are playing the semi-final of the national mixed teams competition, which is (unusually) scored as aggregate, honours counting. Not that that really makes a difference to this hand.

Opponents are good players, have won national events in England (and in Australia) but are not top class.

LHO leads a high heart pip (obviously a doubleton) to the jack and your ace.
You observe that, assuming they don't have/can't find a club ruff
- leading a low spade from hand picks up AQx or AQ10 on your left as long as LHO also has the CA. Also sometimes AQ doubleton, except now you know there is a minor suit ruff available if they find it.
- crossing in diamonds to play a spade up picks up Qxx/Q10x on your left.
- leading the SK from hand picks up AQx on your left. However if LHO has A10x or Axx or even A108x in a 4243 they might duck the SK. (Also A10 doubleton on your left except you have to pick it)

AQx or AQ10 on your left is more likely than AQx only. How likely is LHO to duck from Axx, and for you to be right to play for that (rather than play for them to have ducked from AQx)?

How do you play spades?

[gnasher]

Assuming that LHO has ♣A, and RHO doesn't have a singleton club, doesn't low to the jack pick up A82-Q10?

[FrancesHinden]

gnasher, on Apr 6 2008, 04:09 PM, said:

Assuming that LHO has ♣A, and RHO doesn't have a singleton club, doesn't low to the jack pick up A82-Q10?

Yes, but so does starting with the King so that holding is neutral

[nige1]

I guess to win ♥A and lead a low ♠

[gnasher]

FrancesHinden, on Apr 6 2008, 08:07 PM, said:

gnasher, on Apr 6 2008, 04:09 PM, said:

Assuming that LHO has ♣A, and RHO doesn't have a singleton club, doesn't low to the jack pick up A82-Q10?

Yes, but so does starting with the King so that holding is neutral

Well, probably. If you start with the king, LHO wins the ace, RHO plays the 10, and LHO plays another heart, what are you going to do?

If RHO has ♠Q10, a promotion is threatened, so you have to play three rounds of diamonds, throwing a spade. However, that loses if RHO has found an imaginative falsecard or an unimaginative suit-preference signal from 10x KQJxxxx x xxx.

[gnasher]

Back to the original question. I'm going to assume that both aces are on my left, and that if there is a ruff to be had they'll find it. So, I'm only considering layouts where LHO has A?? or A108x in spades.

Leading the king hopes to gain when LHO has A102, A108 or A1082. It breaks even when LHO has AQ2 or AQ8, and most of the time that LHO has A82. It loses when LHO has AQ10.

A factor that you haven't mentioned is that with something like A10x xx xxxx Axxx, LHO might play for his partner to have ♣Kx, winning the first trump and playing a low club. He might reason that with ♠KQxxx and ♣xxx I'd probably start trumps with either the queen or a low one, so leading the king makes it less likely that he'll play for this layout.

From a defender's point of view, with A102, A108 or A1082, it's unlikely that ducking the first trick will defeat the contract - it's hard to construct a reasonable layout where the defence can get four tricks after a duck. However, I'd bet that lots of players would duck, not envisaging the actual layout. I can certainly see myself ducking.

If they misdefend half the time that will be plenty, and the idea is quite attractive, so if I'd managed to think of it quickly enough to make it believeable, I'd lead the king, prepared to look foolish if LHO has AQ10. After all, it's only a mixed teams.

I doubt, though, that I'd have thought of it in time.

[xcurt]

I've never played aggregate, but don't we have to consider the chances of getting out for -1 at this form of scoring, or at least consider them more than we would at IMPs?

If we lead to the J and a trump comes back, RHO having Qx, we might lose 6 tricks. That would be triple-dummy defense, but if there it's likely RHO would find it we might be better off starting with the K

Extra down vs 620 is only 1 or 2 IMPs (-100 is lose 12, -200 13, -300 14). At aggregate the result at the other table on this board is immaterial. We only care that our total score plus teammates total score is a positive number.

Or is 200 points not a big deal at aggregate? How big is a normal winning margin?

[FrancesHinden]

xcurt, on Apr 8 2008, 02:27 AM, said:

I've never played aggregate, but don't we have to consider the chances of getting out for -1 at this form of scoring, or at least consider them more than we would at IMPs?

Extra down vs 620 is only 1 or 2 IMPs (-100 is lose 12, -200 13, -300 14). At aggregate the result at the other table on this board is immaterial. We only care that our total score plus teammates total score is a positive number.

Or is 200 points not a big deal at aggregate? How big is a normal winning margin?

While it's true that extra undertricks are more expensive compared to imps if the other side is making game, the cost of not making game is much higher - vulnerable games are more important at aggregate than at imps, partials less so.

Just like imps winning margins vary a lot, but a rough conversion factor over a long match is 50 aggregate points ~ 1 imp. There is more volatility than at imps, of course.