| How-to use BRidgeBRowser
DAY TWO |
| Question 2:
You have a five-card heart suit after partner opens 2NT showing 20-22. Should you aim to play in 4H or 3NT if he has 3-card heart support? One big difference between this and Question 1 is that this is eminently suitable for a BIDDING search, because 2NT openers are relatively rare, we don't have to slog through the entire bidding sequence database looking at stuff and discarding it (not too bad on your own computer, but online will take forever). Also, this kind of search includes all openers in 1st,2nd,3rd and 4th seats. OK, let's do it: |
| 1. Fire up BRBR Online. The latest version is 2.3A-h-4 |
| 2. Select S(can R(eset All (only need to do this once, just make sure you havent restricted all your searches on some previous visit) |
| 3. Click on the tab about halfway down, BELOW "BRidgeBRowser (tm)" which says "Bidding". |
| 4. Set the first two squares (use right-click) to 2NT 2NT. This will request an opening bid which is >= 2NT and <= 2NT. |
| 5. Under "Open >=" in the second row, adjust HCP to 19. Opener now has at least 19 and this will exclude the 2NT openers on preemptive or two-suited hands. |
| 6. Still under the opener's seat (first two columns) in the row marked hearts, adjust the lower range to 'xxx' and the upper range to 'AKQ' |
| 7. In the first row, set both opps ("Over" and "Advc) to "Pass" both lower AND upper limits. Set Resp >= to be 3C with no upper limit |
| 8. Give responder 5-9 HCP (second row). |
| 9. Under "Resp >=" and "Resp <=" set the heart holding to be >= xxxxx and <= AKQJx |
| 7. Go to the "Bid analysis" tab and enable it by checking the "Enable as auxiliary term" box. |
| 8. Go to the "View" and select "Declarer" in the "View from" button. Check "Enable as auxiliary term". Click on the "Bidding" tab one more time. |
| OK, now we are ready to search. Your screen's lower half should look
about like this
Press Search. You should get 1897 hand records if you use the default data set online (2003b) You can double click on a hand in the top portion of the screen, just for fun, to verify that the hands being returned conform to your search parameters. (use the F1 key to see how the hand screen works if you didnt already). If something is wrong, press STOP and review steps 3 through 7. Wait till it finishes, there should be a beep. |
| RESULTS
We're not done yet. We need to interpret the results. You can start
to do so while the results accumulate, but be careful not to initiate anything
until the search is finished. This is particularly important for bidding
searches, which are in the order of the bidding sequence. In a nutshell,
by stopping early you would exclude any hands that ended in higher contracts
than where you stopped. (eg the first 200 hands might go 2NT P P P - not
in this case since responder has 5+ points)
|
| 1. Go to the "Bid analysis" tab. If your screen is big enough, stretch
the window downwards by grabbing the bottom, thus:
I carefully moved the "slider" above the table (not visible in the graphic) to "CtrOS" (Contract Opener's Side) so now the statistics relating to contracts are displayed in the 4 columns at the right. 511 folks played in 3NT, for +1.07 imps or 56.99% matchpoints 1057 played in 4H, for +0.13 imps or 51.09%. Assorted players were in contracts all the way up to 7NT. If you are
intrigued by any of these (eg the players who managed to play in 5NT?,
you can substitute that cell instead when following instructions below).
|
| 2. Put the mouse on the number "1057" (4H-CtrOS) and right-click. Select the first option (All hands). The 4H contracts should now appear in the main screen. |
| 3. Click on the Hand Stats tab, and check "Enable as auxiliary
term". The table should now populate (see below). If you check the box
marked "full trick stats" you should magically reveal the trick table as
follows (scroll over for the MP results):
You may wish to export this lot to Excel using the "Write Report" button I hope you found yesterday. |
| 4. To look at the results for 3NT: (DO NOT PRESS "Clear Results" or
you lose the bidding analysis table)
a. UNcheck the "Full trick stats" box and UNcheck the "Enable as auxiliary" tab. b. Click on the "Bid Analysis" tab. c. Right click on 511 (3NT - CtrOS) and select "All Hands" again. d. Click on "Hand Stats" and check the "Enable" box. Notice that the last two columns of all four tables are blank, because this is a NoTrump contract. e.. Check the "Full trick stats" box.
|
| CONCLUSION:
You should not work too hard to play in 4H just because you have a 5-3 fit? I hope this is useful. Please write to me and tell me what you didn't understand. Here's the email again Stephen Pickett |
| NOTES: |
| 1. If you want to include the same boards where people opened other
than 2NT, it gets more complicated, because now you have to save the intermediate
file containing the boards, and then search every sequence on those boards.
I've done it, and the results appear substantially the same. Only those
with a "real" BRBR (not the online version) can even start to do this.
Another point which is sure to be raised, is that relatively few BOARDS
are involved. You can try again on each of the other data sets (again,
I've done it), and the results will be approximately similar. The Standard
Deviation (actually Standard Error of the Mean which is S.D. divided by
SQRT[N]) is small enough that you can be reasonably confident even from
these numbers.
|
| 2. You should (always) get the latest client.
that address again: |
| 3. Now you can go back and ask the same question where the opener and responder both have SPADES. |
| HERE'S THE NEXT ONE, DAY 3 |
