Minors and Matchpoints

[rod]

Matchpoints, nobody vulnerable, you pick up as dealer:

♠ K42
♥ K5
♦ AQ10987
♣ 64

You open 1♦, LHO bids 2♣, partner doubles and RHO bids 4♣.

Your call.

[rod]

This is an exercise in matchpoint thinking. I think many players would pass. But let's consider some points.

1. The only case for passing is if 4♣ makes and 4♦ is down two or more doubled. This seems unlikely because your side has at least half the points.

2. All of your cards are working on offence. Partner has announced support for the unbid suits and you have the King of each.

3. The opponents have a lot of clubs, so partner is likely to have a singleton and some diamond support.

Bidding looks better than doubling. So compete for the partscore with 4♦. Partner should know that at matchpoints this is not a game try. If you pass, partner will have no clue that your diamonds are this good and will likely also pass.

The full deal was:

♠ Q1085
♥ Q10432
♦ KJ5
♣ 10

♠ A963
♥ A9
♦ 62
♣ KQJ83

♠ J7
♥ J876
♦ 43
♣ A9752

♠ K42
♥ K5
♦ AQ10987
♣ 64

They might have beat it with perfect defense, but you'll never win if your opponents consistently play that well.

I might double instead of bidding if the opponents were vulnerable. Would you?

[HDZ7]

Partner has minimum 8 points. RHO 4C bid suggests 5 clubs and some values and Diamond shortage. So the question is guessing if the partner has one of the 2 missing Aces (S & H) and if so then then 3 to 5 defensives tricks would be plausible (1 or 2D, 2 or 3M), hence DBl is reasonable. However I would not like to take this chance even at vulnerability as if partner has an Ace then 4D has a good chance of making. If not 4C has a good chance of making.

Happy to hear your views.