Main   Study 9X00 by Richard Pavlicek  

Opening Bid Comparisons

This study compares opening-bid choices in 72 major events from 1996 to 2014. Source data consists of 40,069 deals (80,138 results) from vugraph archives of the Vanderbilt, Spingold, U.S. Championship and World Team Championship — widely considered to be the four strongest team events each year.

Open Pass1 C 1 D1 C 1 NT1 D 1 NT1 H 1 NT1 S 1 NTSuit 2 NTOne 2 COne TwoOne Four

The basic idea is to consider only cases where a hand was opened differently at one table than the other, then determine which of these two actions was the long-term winner. Results are broken down by table position (first, second or third seat) and HCP where appropriate. Results based on minimal data may be unreliable but otherwise should be meaningful, because all participants were experts, including the world’s best.

In this study the meaning of a bid is not considered, however, choices within the same comparison have a like relationship in the great majority of cases. For instance, if a hand is opened 1 H at one table and 1 NT at the other, it is almost always a balanced hand with five hearts. Similarly, if a strong hand is opened 1 C at one table and 2 C at the other, it is invariably a big-club versus standard system.

The winning choice for each comparison is tinted gold to aid recognition. To view the actual deals for any comparison, click on the number in the Cases column.

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Open vs Pass

The following table compares cases where a hand was opened at Table 1 but passed at Table 2. Essentially this is an assessment of light opening bids, which are broken down by position and strain. (Fourth seat is ignored, as passouts were rare.)

The general picture is that opening light in a minor or notrump fares better than passing. In a major, however, this is true only in first seat, though the numbers for 1 S are very close.

Most remarkable is that opening light in hearts scored 61+ percent in first suit, but in second or third seat it’s a complete turnaround favoring the pass. Go figure.

SeatHCPCasesTable 1IMPsPercentTable 2IMPsPercent
Firstany3761 C80849.60Pass82150.40
Firstany6051 D159255.30Pass128744.70
Firstany2421 H69361.49Pass43438.51
Firstany2311 S61751.94Pass57148.06
Firstany1881 NT46553.82Pass39946.18
Secondany1531 C40461.59Pass25238.41
Secondany2801 D73157.70Pass53642.30
Secondany1331 H26640.00Pass39960.00
Secondany881 S19348.13Pass20851.87
Secondany831 NT17455.06Pass14244.94
Thirdany1071 C23959.60Pass16240.40
Thirdany1641 D34155.63Pass27244.37
Thirdany921 H15637.41Pass26162.59
Thirdany761 S15450.00Pass15450.00
Thirdany91 NT2866.67Pass1433.33

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One Club vs One Diamond

The following table compares cases where a hand was opened 1 C at Table 1 and 1 D at Table 2, subdivided by position and HCP range. In many cases this was dictated by system (e.g., nebulous 1 D because 1 C is strong) so it’s not clear whether this provides any useful evidence — but interesting nonetheless.

SeatHCPCasesTable 1IMPsPercentTable 2IMPsPercent
First10-111221 C25154.331 D21145.67
First12-136591 C127054.131 D107645.87
First14-151261 C22643.711 D29156.29
First16-171221 C33360.001 D22240.00
Second10-11731 C12447.691 D13652.31
Second12-133491 C69751.551 D65548.45
Second14-151021 C22757.181 D17042.82
Second16-17771 C13441.611 D18858.39
Third10-11381 C9481.031 D2218.97
Third12-131541 C29553.151 D26046.85
Third14-15571 C15366.231 D7833.77
Third16-17331 C9354.711 D7745.29

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One Club vs One Notrump

The following table compares cases where a hand was opened 1 C at Table 1 and 1 NT at Table 2, subdivided by position and HCP range. In most cases the differences relate to system, i.e., with balanced hands (and some nearly so) 1 NT would be routine if the range fits your system.

Results suggest that the weaker the hand, the more desirable it is to open 1 NT, with a few anomalies thrown in related to position. Party time for weak notrumpers? Maybe, but being in the opposite camp I’ll pass on hosting the occasion.

SeatHCPCasesTable 1IMPsPercentTable 2IMPsPercent
First10-133501 C62844.041 NT79855.96
First14-154231 C88252.221 NT80747.78
First16-173181 C66059.351 NT45240.65
Second10-131801 C30447.431 NT33752.57
Second14-152481 C44647.051 NT50252.95
Second16-172271 C49356.281 NT38343.72
Third10-13401 C5938.061 NT9661.94
Third14-151381 C24448.411 NT26051.59
Third16-171321 C22847.401 NT25352.60

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One Diamond vs One Notrump

The following table compares cases where a hand was opened 1 D at Table 1 and 1 NT at Table 2, subdivided by position and HCP range. Except for a few narrow losses, 1 NT has the clear edge.

SeatHCPCasesTable 1IMPsPercentTable 2IMPsPercent
First10-133861 D73244.581 NT91055.42
First14-153071 D58445.881 NT68954.12
First16-17661 D12747.391 NT14152.61
Second10-131561 D28448.461 NT30251.54
Second14-151851 D26340.401 NT38859.60
Second16-17531 D11551.801 NT10748.20
Third10-13601 D11250.681 NT10949.32
Third14-15901 D15147.631 NT16652.37
Third16-17291 D5640.881 NT8159.12

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One Heart vs One Notrump

The following table compares cases where a hand was opened 1 H at Table 1 and 1 NT at Table 2, subdivided by position and HCP range. Except for third seat (and the highest range in second suit) it follows the general expert consensus that balanced hands with five hearts are better opened 1 NT if in range. One reason is to avoid rebid problems, and another is to shut out a 1 S overcall.

SeatHCPCasesTable 1IMPsPercentTable 2IMPsPercent
First10-13641 H8836.071 NT15663.93
First14-151141 H20346.671 NT23253.33
First16-17211 H2943.941 NT3756.06
Second10-13281 H6944.231 NT8755.77
Second14-15711 H10936.331 NT19163.67
Second16-17181 H3367.351 NT1632.65
Third10-13161 H3262.751 NT1937.25
Third14-15321 H5752.291 NT5247.71
Third16-17101 H3861.291 NT2438.71

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One Spade vs One Notrump

The following table compares cases where a hand was opened 1 S at Table 1 and 1 NT at Table 2, subdivided by position and HCP range. Unlike the previous scenario with hearts, opening 1 S is the overall winner, though not without a few curious twists.

SeatHCPCasesTable 1IMPsPercentTable 2IMPsPercent
First10-13391 S9161.071 NT5838.93
First14-15701 S15057.031 NT11342.97
First16-17221 S1730.361 NT3969.64
Second10-13261 S6977.531 NT2022.47
Second14-15401 S6139.101 NT9560.90
Second16-17151 S5371.621 NT2128.38
Third10-13121 S1943.181 NT2556.82
Third14-15171 S2555.561 NT2044.44
Third16-17121 S1850.001 NT1850.00

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One of Suit vs Two Notrump

The following table compares cases where a hand was opened one of a suit at Table 1, and 2 NT at Table 2. Typically this compares a staid one-bid with an aggressive 2 NT, usually based on a 5+ card suit to offset the high-card deficiency — except for 1 C, which in most cases was strong and artificial (dictated by system) so not a useful comparison. In second suit 2 NT fared better than any suit opening, but in first and third it’s a mixed bag.

SeatHCPCasesTable 1IMPsPercentTable 2IMPsPercent
Firstany1651 C36050.212 NT35749.79
Firstany431 D8435.152 NT15564.85
Firstany101 H2083.332 NT416.67
Firstany111 S2558.142 NT1841.86
Secondany1111 C12729.402 NT30570.60
Secondany151 D3748.052 NT4051.95
Secondany91 H1320.972 NT4979.03
Secondany71 S240.002 NT360.00
Thirdany771 C11145.312 NT13454.69
Thirdany151 D4361.432 NT2738.57
Thirdany61 H1361.902 NT838.10
Thirdany41 S133.332 NT266.67

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One of Suit vs Two Clubs

The following table compares cases where a hand was opened one of a suit at Table 1, and 2 C (strong) at Table 2. For 1 D, 1 H and 1 S this is almost always a “borderline 2 C opening” decided differently at the two tables. For 1 C, however, the comparison is biased, because it also includes strong-club openings.

I was surprised to see 2 C fare better than 1 C (except for a narrow first-seat loss) as the reduced bidding space should be a disadvantage — or at least that’s the hype of most big-club advocates. The comparison isn’t fair, however, because when the two bids coincide the strength of 2 C is more narrowly defined. No doubt 1 C forcing would fare much better than one of a suit on the 16-21 HCP range.

SeatHCPCasesTable 1IMPsPercentTable 2IMPsPercent
First16-371321 C27450.462 C26949.54
First16-37121 D57.352 C6392.65
First16-3761 H2450.002 C2450.00
First16-37141 S5865.912 C3034.09
Second16-37851 C16038.462 C25661.54
Second16-37121 D2326.442 C6473.56
Second16-3761 H315.002 C1785.00
Second16-37101 S15.562 C1794.44
Third16-37721 C11232.562 C23267.44
Third16-3751 D2460.002 C1640.00
Third16-3711 H002 C17100
Third16-37101 S2944.622 C3655.38

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One vs Two of Suit

The following table compares cases where a hand was opened one of a suit at Table 1, and two of the same suit at Table 2. The choice between 1 C and 2 C is almost always a natural 1 C vs. Precision 2 C, since the 9-15 HCP range precludes strong hands.

In the other three suits the choice was typically between a light one-bid and a weak two-bid, but the auctions are not individually screened, so various anomalies slip through such as two-suited two-bids (including 2 H Flannery).

It is curious how position plays a significant role (except for hearts). Who would have thought that a natural 1 C beats 2 C only in second seat? Further, there is no consistency among the suits, as each has a unique pattern regarding position.

SeatHCPCasesTable 1IMPsPercentTable 2IMPsPercent
First9-153121 C70246.992 C79253.01
First9-15751 D17158.762 D12041.24
First9-151771 H31141.802 H43358.20
First9-151381 S25044.562 S31155.44
Second9-151501 C37952.642 C34147.36
Second9-15271 D5236.112 D9263.89
Second9-15821 H12742.192 H17457.81
Second9-15631 S16057.552 S11842.45
Third9-15571 C6829.442 C16370.56
Third9-15181 D3036.592 D5263.41
Third9-15501 H10238.492 H16361.51
Third9-15251 S4854.552 S4045.45

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One vs Four of Major

The following table compares cases where a hand was opened one of a major at Table 1, and four of the same major at Table 2, which obviously compares “going slow” versus preempting. Except for the cases in second seat, preempts show a profit. Data is sparse, however, so it’s too early to bet the farm.

SeatHCPCasesTable 1IMPsPercentTable 2IMPsPercent
Firstany291 H5333.334 H10666.67
Firstany291 S5135.924 S9164.08
Secondany71 H1789.474 H210.53
Secondany81 S2580.654 S619.35
Thirdany71 H816.674 H4083.33
Thirdany141 S3347.144 S3752.86

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© 2014 Richard Pavlicek