Posted 2012-March-30, 02:15
There's a risk of a trump squeeze if declarer has xx Axxx AQxx Jxx or Jx Axxx AQx 10xxx. For this to work, he has to have four hearts, because it needs two entries to dummy after cashing the side winners. However, if that's the layout there's nothing I can do about it, and anyway I expect RHO would have shown his hearts instead of bidding 2♠.
If declarer has Jx Axx Axxx J109x (or clubs as bad as J97x), I have to switch to a diamond now to stop him setting up the club winner. On a trump switch he wins the jack, leads ♣J covered and ruffed, draws trumps, and uses his two aces to set up and cash the long club. The diamond switch removes one of his non-trump entries prematurely.
However, that requires him to have a fairly specific hand: ♠J, no ♥10, no ♦Q, and good enough clubs. The diamond switch would let it through if he had Jx Axx AQxx 109xx, which looks more like a balanced invitation. Hence I think it's better to defend passively.
dwar0123: I think you may have misunderstood the diagram. Dummy is on our left.
... that would still not be conclusive proof, before someone wants to explain that to me as well as if I was a 5 year-old. - gwnn