Main     Study 9X41 by Richard Pavlicek    

Opening Bid Summary

Comparison of opening-bid choices in 65 major events from 1996 to 2012 produced some interesting results. Some of these were predictable, but a few surprises suggest winning advice that I have not seen in print elsewhere. Source data consists of 66,652 results (33,326 deals) from vugraph archives of the Vanderbilt, Spingold, U.S. Championship and World Team Championship.

For each comparison, results are shown in four time spans: past four years, past eight years, past 12 years, and all data (17 years). Changing percentages and/or winners over time sometimes reveals a trend. Click the button at the right of each table to view the actual deals.

Analyses for light openings (versus pass) considered first and second seat only, since strategy differs greatly in third and fourth seat. All other analyses included openings in any position.

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Open Light or Pass?

One team opened one club, other passed

YearWinnerBoardsIMP PercentWLT Percent
2009-2012Open 1C173369-342 = 51.9070-61-42 = 52.60
2005-2012Open 1C294639-585 = 52.21115-105-74 = 51.70
2001-2012Open 1C361794-718 = 52.51140-128-93 = 51.66
1996-2012Open 1C420945-888 = 51.55166-152-102 = 51.67

One team opened one diamond, other passed

YearWinnerBoardsIMP PercentWLT Percent
2009-2012Open 1D327886-642 = 57.98147-119-61 = 54.28
2005-2012Open 1D4801256-932 = 57.40209-174-97 = 53.65
2001-2012Open 1D5701490-1160 = 56.23245-212-113 = 52.89
1996-2012Open 1D6571705-1356 = 55.70280-248-129 = 52.44

Evidence suggests that opening light in a minor, especially diamonds, is a winning strategy.

One team opened one heart, other passed

YearWinnerBoardsIMP PercentWLT Percent
2009-2012Pass123336-278 = 54.7255-46-22 = 53.66
2005-2012Pass188459-452 = 50.3872-75-41 = 49.20
2001-2012Open 1H248586-558 = 51.2299-90-59 = 51.81
1996-2012Open 1H293705-671 = 51.24118-106-69 = 52.05

Opening light in hearts is probably a winning strategy, but the shift in the most recent four years casts some doubt.

One team opened one spade, other passed

YearWinnerBoardsIMP PercentWLT Percent
2009-2012Pass99270-220 = 55.1040-35-24 = 52.53
2005-2012Pass162441-405 = 52.1362-63-37 = 49.69
2001-2012Pass218556-530 = 51.2085-83-50 = 50.46
1996-2012Pass258692-665 = 50.99104-97-57 = 51.36

Opening light in spades, however, leaves little doubt as being a losing strategy. Why so? Opening light in any suit makes constructive bidding less accurate due to the wider range of opener’s hand. This is offset by the advantage in bidding first. When you hold the highest ranking suit, the advantage in bidding first is minimal (you can usually bid later) and the detriment to constructive bidding is maximal (fewer bids remain for exploration). At least that’s my take on it.

One team opened one notrump, other passed

YearWinnerBoardsIMP PercentWLT Percent
2009-2012Pass73147-116 = 55.8934-24-15 = 56.85
2005-2012Open 1NT115238-234 = 50.4244-49-22 = 47.83
2001-2012Open 1NT167372-351 = 51.4564-72-31 = 47.60
1996-2012Open 1NT237533-489 = 52.1592-94-51 = 49.58

Evidence suggests the kamikaze or mini notrump (10-12) is a losing strategy. While opening 1 NT has a slight edge over 17 years, pass has the edge in more recent time spans. Perhaps this means that defensive measures have caught up and put this rogue bid out to pasture. Note that pass has always worked better in the win-loss column.

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Five-card Major or Notrump?

One team opened one heart (5+), other one notrump

YearWinnerBoardsIMP PercentWLT Percent
2009-2012Open 1NT111196-154 = 56.0047-37-27 = 54.50
2005-2012Open 1NT164328-255 = 56.2669-56-39 = 53.96
2001-2012Open 1NT214462-318 = 59.2393-70-51 = 55.37
1996-2012Open 1NT249547-390 = 58.38108-84-57 = 54.82

One team opened one spade (5+), other one notrump

YearWinnerBoardsIMP PercentWLT Percent
2009-2012Open 1S85191-109 = 63.6736-29-20 = 54.12
2005-2012Open 1S146317-188 = 62.7760-49-37 = 53.77
2001-2012Open 1S165345-215 = 61.6165-55-45 = 53.03
1996-2012Open 1S183377-265 = 58.7271-63-49 = 52.19

Evidence strongly suggests to open 1 NT with hearts but not spades. Experts have long been aware of the rebid problem after a balanced 1 H opening, but the extreme difference compared to spades is remarkable.

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Weak or Strong Notrump?

One team opened one notrump (12-14), other one of minor

YearWinnerBoardsIMP PercentWLT Percent
2009-2012Weak NT444825-801 = 50.74165-173-106 = 49.10
2005-2012Weak NT7461377-1361 = 50.29278-284-184 = 49.60
2001-2012Weak NT9751815-1692 = 51.75368-357-250 = 50.56
1996-2012Weak NT11622217-2030 = 52.20436-423-303 = 50.56

One team opened one notrump (15-17), other one of minor

YearWinnerBoardsIMP PercentWLT Percent
2009-2012Minor321636-519 = 55.06118-107-96 = 51.71
2005-2012Strong NT522929-921 = 50.22194-173-155 = 52.01
2001-2012Minor6631234-1133 = 52.13222-235-206 = 49.02
1996-2012Minor7931491-1413 = 51.34268-285-240 = 48.93

Evidence suggests that weak notrumps are better. Test ranges were 12-14 (weak) and 15-17 (strong), and only truly balanced hands were considered in order to focus on system rather than judgment of off-shape patterns. Nonetheless, this comparison is flawed because of overlapping ranges, e.g., 13-15 and 14-16, so further analysis may be forthcoming — says the lifelong strong notrumper.

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What Flavor Two Diamonds?

One team opened Flannery two diamonds, other did not

YearWinnerBoardsIMP PercentWLT Percent
2009-2012Flannery54159-96 = 62.3523-17-14 = 55.56
2005-2012Flannery74221-143 = 60.7130-27-17 = 52.03
2001-2012Flannery91255-179 = 58.7636-34-21 = 51.10
1996-2012Flannery109314-224 = 58.3642-41-26 = 50.46

One team opened Multi two diamonds, other did not

YearWinnerBoardsIMP PercentWLT Percent
2009-2012Not97223-199 = 52.8433-35-29 = 48.97
2005-2012Multi165371-362 = 50.6161-55-49 = 51.82
2001-2012Multi237548-476 = 53.5292-76-69 = 53.38
1996-2012Multi293695-642 = 51.98109-102-82 = 51.19

One team opened a weak two diamonds, other did not

YearWinnerBoardsIMP PercentWLT Percent
2009-2012Weak 2D88268-167 = 61.6143-27-18 = 59.09
2005-2012Weak 2D139377-297 = 55.9359-46-34 = 54.68
2001-2012Weak 2D178481-309 = 60.8982-49-47 = 59.27
1996-2012Weak 2D211552-388 = 58.7296-64-51 = 57.58

Evidence appears to favor Flannery over a natural weak two-bid, with multi far behind; but results are tainted in several ways. First, the use of any convention affects auctions besides those in which in occurs. For example, multi users do not expect to profit in opening 2 D, but from the ability to use 2 H and 2 S for other purposes. Second, a scan of the Flannery camp reveals more top pairs than either of the others, so its IMP percent has a high-octane boost.

The fact that each camp beats its opposition in direct comparison is no surprise. No matter what you play, when hands come up to fit your system, you will show a profit — well, except for the Jacobs lead-director (see Weak 2 D #42).

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One or Four of Major?

One team opened one heart, other four hearts

YearWinnerBoardsIMP PercentWLT Percent
2009-2012Open 4H1151-12 = 80.958-1-2 = 81.82
2005-2012Open 4H2193-54 = 63.2713-5-3 = 69.05
2001-2012Open 4H27119-57 = 67.6116-7-4 = 66.67
1996-2012Open 4H32122-60 = 67.0317-9-6 = 62.50

One team opened one spade, other four spades

YearWinnerBoardsIMP PercentWLT Percent
2009-2012Open 4S2793-69 = 57.418-10-9 = 46.30
2005-2012Open 4S3199-70 = 58.589-11-11 = 46.77
2001-2012Open 4S35116-70 = 62.3711-11-13 = 50.00
1996-2012Open 4S42119-93 = 56.1313-15-14 = 47.62

Evidence clearly favors the preempt, though available data is limited.

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© 2012 Richard Pavlicek