I must be missing something here. The diagram says I am SOUTH.
East has a trump trick (West showed out). How can I 'guarantee' -1? If I give him his heart trick 1st, I'm losing a spade, 2 diamonds and heart. If I try to unblock the K
♣ 1st, I'm still losing a spade, 2 diamonds and a heart.
On this layout I need East to hold at least 3 clubs so I can ditch TWO diamonds before he ruffs in.
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(If WEST has the trump trick, (and there is a typo in the diagram) then I suppose the question posed is correct). You can lose the club ruff, they cash diamond, diamond, spade and get an overruff with the Q
♥; -3; -150. If West follows to the 2nd club, then you make 7, +510. There's nothing in the bidding to guide you here, although I suppose if West thought that he has you beat in 5
♥, while 5
♠ is dubious, then its certainly more likely he holds a stiff.
From an IMP odds standpoint, if you think the auction and lead are the same as the other table, then try to make your contract. By exchanging -1 for -3 NV, you are sacrificing 3 IMPs. OTOH, going down in a cold game (actually with two overtricks), you are risking 10 IMPs for insuring -1. Would you wager 10:3 that the lead is a stiff? Maybe, but I don't think its indicated.
Since so much can happen here, I think you are taking a view that -1 undoubled rates to be a good score.
If you were doubled this is a whole different kettle of fish; now you are risking -500 when -100 is achievable.
The comment about 5
♠ being cold is 100% correct, but only if the lead is a stiff. Maybe you gave away too much information when you said that.
1♥-(p)-2♥-(2♠)
5♥-all pass