Board 8
West Deals
None Vul |
| ♠ | Q 10 5 3 |
| ♥ | Q 7 |
| ♦ | A 7 6 4 2 |
| ♣ | 10 2 |
|
| ♠ | K J 7 2 |
| ♥ | A J 8 3 |
| ♦ | K 10 9 |
| ♣ | K 5 |
| |
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| ♠ | 8 6 |
| ♥ | K 10 9 |
| ♦ | Q 3 |
| ♣ | A Q 8 7 6 4 |
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| ♠ | A 9 4 |
| ♥ | 6 5 4 2 |
| ♦ | J 8 5 |
| ♣ | J 9 3 |
|
EW 5N; EW 5♥; EW 5♣; EW 3♠; W 2♦; E 1♦; Par −460
| West | North | East | South |
| 1 NT | Pass | 3 ♣ | Pass |
| 3 ♥ | Pass | 3 NT | All pass |
West has a 15hcp hand so 1 NT is not ACOL.
This type of bidding normally indicates a longish club suit by east, with west showing hearts. Note that the heart bid is possibly unneccesary as if east had a 4 card major they would have used stayman. The heart bid gives information to the oppo and helps especially with opening lead.
As to opening lead, the lead of the longest suit is not unreasonable, but a) a major suit bias exists in auctions like these and b) the suit is poor quality and outside entries are poor, conversely the AD is a good outside entry to help establish spades. I will do further analysis on this, but initial impression is that S3 might be best.
At another table the bidding went: 1H 2C 2 NT 3H 3 NT. This is good ACOL bidding. 2NT is a GF with 15+, while 3H shows 3 card support in case there is a 5-3 fit.
Further analysis indicates that at IMPs the difference between a spade lead and a diamond is.... lineball. Both are vastly superior to other suit leads. At MPs however a spade lead is slightly superior. To explain what is going on here, I first use a programme called Dealer to randomly select a number of hands (I typically choose 5000) based on certain constraints according to the bidding and the opening leaders hand. I then get an app called Bridge Analyser to perform double dummy analysis(DDA) on each hand with each of 4 suit leads, so 20,000 results. For IMPs the proxy I use is the number of times the lead beats the contract, assuming perfect declarer and defence play. Here, eg both spade and diamond leads led to the contract failing 38% of the time vs <25% for the other leads. At MPs the proxy I use is average tricks taken. Here, spades was better than diamonds by 0.1 tricks, and better than the others by >0.5 tricks. 0.1 might not sound much, but consider a 25 session MP results where on 2-3 bds u get a top result by playing the best lead - turns an average session into a good session quickly.
ReplyDeleteDid you factor in that opener is quite likely to have four spades on this auction? When west opens hearts and rebids no trumps and then denies five hearts the only shapes possible are precisely 3=4=3=3 or 4=4=3=2 or 4=4=2=3. I think 4=4 in the majors is therefore more common - not quite twice as common.
ReplyDelete