The Opening Bid


Author: Larry Cohen
Date of publish: 07/01/2010
Level: All Levels

In this series, we are analyzing 1,000,000 deals which were played on-line. These deals cover a wide range of level of play and were provided by Stephen Pickett with Bridge Browser.

 

What is the most likely opening bid?



Let's start at the very beginning: 1? is the winner. Of course, some of this is influenced by system. Players using a strong club system open 1? on all good hands. Balancing that out to some effect, is the fact that they also open all minimum hands (that don't fit 1NT or 1MAJ) with 1?.


1? was opened on 22.7 % of all deals, just slightly ahead of 1? on 21.31%.   So, the opening bid is 1 of a minor on almost half of all bridge deals!


Some questions with logical answers:



Which is more likely to be opened:  1? or 1??  Logically, there is an equal chance of getting dealt 5 spades or 5 hearts. However, a 1? opener is more likely for two reasons:  1) with 5-5 you open 1? not 1?, and 2) Since some people use the Flannery convention (whereby a hand with 5 hearts and 4 spades is opened 2?), that slightly cuts down on the number of 1? openers.  The data bear this out, as 1? was opened roughly 7,500 more times than 1? on the 1,000,000 deals.



Here's another question with a logical answer: Which is more likely--a 3-of-a-minor opening or a 3-of-a-major opening? Since most people use 2? (and a few use 2?) as conventional, there is no way to open weak two bids there. That puts more weight on the 3-bid. Conversely, most players can preempt on the 2-level with a major, so there should be fewer 3-level preempts in majors. Again, the data correlate. A 3-level preempt in a minor occurred on 37% more deals than a 3-of-a-major preempt.


For the curious-minded, here is the full report--there are even more logical conclusions that can be drawn.


 OPENING% out of 1 MILLION DEALS
 1?22.68
 1?21.31
 1?15.54
 1?16.31
 1N11.68
 2?  2.02
 2?  1.32
 2?  2.02
 2?  2.05
 2N 1.85
 3?  0.69
 3?  0.68
 3?  0.52
 3?  0.47
 3N  0.10
 4?  0.04
 4?  0.05
 4?  0.32
 4?  0.27
 Higher  0.08