[quiddity]

jdonn, on Mar 19 2009, 03:16 PM, said:

I guess I don't understand why someone would even play jacoby transfers if they are not choosing hearts with ATx and an unstopped doubleton.

The unstopped doubleton has secondary honors, so partner (who rates to have some length and points in diamonds) is less likely to need a 3rd-round ruff. The HA is another indicator for 3nt, since it means you'll be able to establish heart tricks without losing the lead too many times. The HT makes trump-promotion plays less likely, but also improves the chances of establishing heart tricks at NT.

Although I would bid 4H at matchpts, I think I might bid 3NT at imps. If partner had bid 3NT instead I would certainly pass at imps, and perhaps also at matchpts. Anyway, Han, I'm interested in the results of a sim; what are the chances that hearts are 2 tricks, 1 trick, or zero tricks better than NT when partner has 8-9 or 10-14 HCP?

[hanp]

I dealt 1000 hands, partner holding 8 HCP every time and 1-3 spades, 5 hearts, 1-4 diamonds and 1-4 clubs.

4H made on 43% of them.

4H was better than 3NT on 625 hands, worse on 297 hands and equal on 78.

Of course if you expect partner to have 9 HCP often then the percentage of hands where 4H will make should be higher. The difference between 3NT and 4H was so large that I didn't think it was worth to rerun for 9 HCP.

Keep in mind that these are double dummy results.