[helene_t]

Apparently, the conclusion is that you should declare more.

In 125927 vugraph boards where the same team declared on both tables, the average gain for the declaring team was 0.20 IMPs, 95% confidence interval 0.16 : 0.24

[smerriman]

You can conclude from those numbers that you score better when declaring than defending.

You can't conclude that "you should declare more". It's certainly mathematically possible that on every hand you defended, bidding higher would have led to scoring worse.

[mikeh]

The problem with merely asserting that ‘those who routinely outbid their opponents outscore them’ is that the reality is far more nuanced than that.

Most top pairs spend an enormous amount of effort on their bidding systems…having one hundred+ pages of densely written notes is pretty much the norm. This effort can lead to spectacular results in constructive auctions.

The same top pairs spend a lot of time on competitive bidding as well….and these days far more auctions are ‘competitive’ than was the case 50 years ago.

The top pairs don’t win simply by bidding more. They win because they have great judgement…they tend to outperform the rest of us by knowing when NOT to bid one more, as much as they do by knowing when to take that extra bid. Anyone who thinks..if it’s close, I should always or almost always bid again is not going to do well absent having acquired truly expert level judgement

For example, at the club the other day my RHO made what he thought was a Law of Total Tricks bid…driving to the 3 level in a competitive auction based on having a 9 card fit.

What he, and many others, seem to forget is that the Law relates to the total tricks available to both sides, playing in each side’s best fit. He was vulnerable and our double collected 500, more than the value of the nv game we weren’t going to bid…yes, we’d have made it because the Law was actually bang-on (it’s often out by a trick or sometimes more).

I doubt that any top player would have gone to the 3-level with a weak hand and flat distribution.

In a related vein, many top pairs have dropped or use rarely the preemptive raise, opting instead for a mixed raise approach. I suspect that this is in part because of going -200 at the 3-level, against a partscore. -200 is uncommon opposite a mixed raise, but many players still use the jump as purely weak.

So…yes…declaring tends to win imps but only when one uses judgement or system.

By all means, allow these statistics to make you consider whether to ‘bid one more’ in a competitive auction….but don’t do so blindly. Maybe bid one more on about 10% of the hands (that percentage, like 83.6% of such statistics, was made up).

[barmar]

 AL78, on 2024-August-18, 01:10, said:

At duplicate it is not the absolute value of the score you get that matters, it is the score relative to all the pairs sitting your way on that board, so being able to get higher scores as declarer is irrelevant. You can theoretically get a 100% board scoring -2000.

I know that, I said "This is why duplicate bridge is not based on total points".

But even in duplicate, that -2000 will only be a good board if most of the opposing field is bidding a making a vulnerable grand slam. This is not common. I'll bet at least 90% of -2000 scores do not matchpoint well (if I were so inclined I could verify this in the BBO records).

[jillybean]

 helene_t, on 2024-August-21, 12:32, said:

Apparently, the conclusion is that you should declare more. Especially when the board is passed out at the other table

In 125927 vugraph boards where the same team declared on both tables, the average gain for the declaring team was 0.20 IMPs, 95% confidence interval 0.16 : 0.24

I don't understand. One team was the declarer at both tables? Ie: NS played at table A, EW played the same board at table B?

[helene_t]

jillybean, on 2024-August-21, 19:15, said:

I don't understand. One team was the declarer at both tables? Ie: NS played at table A, EW played the same board at table B?

Yes, those are the boards I have selected.

Coming to think about it: I could compare the results on those boards to the results from the remaining boards. Since it principle it is possible that the more aggressive bidders are just better players overall and tend to win even if they only declare on one of the tables.

[fuzzyquack]

Apparently -100 is way better than -110 or -140. If you talk solely about the club-level bridge, defense is way softer than already not so inspiring dummy play. So it's apparent than defending 3♥ with NV 4♣ -2 has got lots of appeal since given their defensive skills, few opposing pairs would whack without a trump stack. That leads to the equilibrium where club players often bid like advanced lunatics.

[barmar]

 fuzzyquack, on 2024-August-26, 21:36, said:

Apparently -100 is way better than -110 or -140. If you talk solely about the club-level bridge, defense is way softer than already not so inspiring dummy play. So it's apparent than defending 3♥ with NV 4♣ -2 has got lots of appeal since given their defensive skills, few opposing pairs would whack without a trump stack. That leads to the equilibrium where club players often bid like advanced lunatics.

It's also hard to know when to double part scores, so people often get away with overbidding.

In matchpoints, it's often necessary to make speculative doubles of low-level contrsacts to "protect your part score". You can't let the opponents get away with -100 when you were going to make 110 or 140. But you're risking getting a complete bottom if you don't actually set them.

[johnu]

 barmar, on 2024-August-28, 16:20, said:

It's also hard to know when to double part scores, so people often get away with overbidding.

Never double if the contract is going to make. Always double when the contract is going down.

[barmar]

johnu, on 2024-August-28, 18:06, said:

Never double if the contract is going to make. Always double when the contract is going down.

I don't know why anyone says bridge is complicated, when we have simple rules like this. It's like getting rich in the stock market: buy low, sell high.

[blackshoe]

"Buy stocks. When they go up, sell. If they don't go up, don't buy." -- Will Rogers