[eagles123]

With JT9X opposite Axxxx I assume that the correct play is to finesse to cater for kqx(x) on the left

Please tell me if I'm wrong

My question though is first round it goes J small small Q. On the second round it goes T small ?

What is best finesse or play for kq tight offside

Many thanks

Eagles

[broze]

At this point there are two relevant holdings:

xx - KQ and
Kxx - Q

right? The former holding is slightly more likely to have been dealt than the latter holding so you might reasonably think that it is right to go up with the Ace here. However, it is totally correct to play low. Why?

Because it is a restricted choice situation. RHO could have won either the K or Q from KQ tight so according to restricted choice he is more likely to have stiff queen and this offsets the fact that xx-KQ is (slightly) more likely to have been dealt a priori.

[Stephen Tu]

broze, on 2015-January-19, 12:52, said:

Because it is a restricted choice situation. RHO could have won either the K or Q from KQ tight so according to restricted choice he is more likely to have stiff queen and this offsets the fact that xx-KQ is (slightly) more likely to have been dealt a priori.

The other way to think about it is that finessing twice regardless of which honor won the first trick picks up both stiff Q/stiff K offside, while going up only picks up KQ tight, and the combo of both stiff Q/stiff K is quite a bit more likely than just KQ tight.

[ggwhiz]

I've never had to play this holding without additional context ie. lack of competition in the auction, lack of covering the spade jack means I played the Ace at trick one 99% of the time

[PhantomSac]

Playing the jack to the ace will really impress your teammates when you find a way to lose three tricks in the suit.

That said I suppose it is optimal against opponents who always cover with kqx, that is pretty lol though especially if the jt9xx is in dummy. I am going to guess that you are simply misplaying the suit frequently

[Hanoi5]

ggwhiz, on 2015-January-19, 14:10, said:

I've never had to play this holding without additional context ie. lack of competition in the auction, lack of covering the spade jack means I played the Ace at trick one 99% of the time

You haven`t played enough.

Isn´t this combo explained in ROdwell's book?

[eagles123]

Well the good news is I did finesse just from instinct really and it worked!

many thx all for help on this

[fourdad]

PhantomSac, on 2015-January-19, 15:18, said:

Playing the jack to the ace will really impress your teammates when you find a way to lose three tricks in the suit.

That said I suppose it is optimal against opponents who always cover with kqx, that is pretty lol though especially if the jt9xx is in dummy. I am going to guess that you are simply misplaying the suit frequently

3 tricks in the suit?

[gwnn]

fourdad, on 2015-January-20, 05:19, said:

3 tricks in the suit?

Yep.

JT92
    KQ83
A7654

If you play the jack to the ace, the K, Q, and 8 will all take tricks unless you can endplay east.

[Fluffy]

I guess it transpired already, but you have too many xxx in your original post eagles, the 8 is relevant when the suit is 4-0.

For BILs, the rule of thumb is this: if oyu have a double finesse against KQ or QJ, you are about 75% to score it, however i the first finesse loses you have dropped a bit your chances since you can no longer catch both honnors onside. So Now your chances are around 67%

[ordo1]

The statistics for the division of 4 cards are: 3/1 50%, 2/2 40% and 4/0 10%.
Playing the ace looses only 1 trick in these cases:
2/2 division = 40%
1/3 division, singleton at either side, singleton k or q = half of 50% x 25%
0/4 division fails. Total of 65%.

Now the double finesse:
2/2 with at most 1 honor offside 3/4 * 40% = 30%
1/3 always success = 50%
0/40 all onside = 5% Total of 85%

[ggwhiz]

Hanoi5, on 2015-January-19, 16:03, said:

You haven`t played enough.

Isn´t this combo explained in ROdwell's book?

Hehe, I can't count. Made a slam against some friends by hooking the Queen missing 4 and when they asked me why I said I thought I was missing 5. I'm back to even cause I thought I was missing 3 here.

At least it's a good insult if I really dislike my lho.

[H_KARLUK]

eagles123, on 2015-January-19, 12:42, said:

With JT9X opposite Axxxx I assume that the correct play is to finesse to cater for kqx(x) on the left

Please tell me if I'm wrong

My question though is first round it goes J small small Q. On the second round it goes T small ?

What is best finesse or play for kq tight offside

Many thanks

Eagles

Hi, when opponents have 4 cards 2-2 division is 40% probability but 3-1 is %50. In that 4 cards stiff honor probability is 12%, doubleton is 40% and trebleton is 38%. General rule for hook is when opponents have 3 or 4 cards hook against the K but not against the Q or J. I bet y'all take it out from there. Have fun!

[ArtK78]

This is not a difficult problem, especially when you have a suit combination calculator such as the one at http://www.automaton.../en/OddsTbl.htm.

If you are missing the KQ8x of a suit (where x is any card lower than the 8), taking 2 finesses will succeed in limiting the tricks lost in the suit to one 71.217% of the time. Playing the Ace first will succeed in limiting the tricks lost in the suit to one 65.566% of the time.

If you strengthen your side's holding by including the 8, so that the opponents hold the KQ76 or worse, taking 2 finesses will succeed in limiting the tricks lost in the suit to one 76% of the time. Playing the Ace first will have the same rate of success as before - 65.566% of the time.

The only relevant holdings in the first case are KQx onside and KQ doubleton offside (x is any card available given the parameters above). KQx onside occurs 12.434% of the time, while KQ doubleton offside occurs 6.783% of the time. The difference - 5.651% - is the difference between the success rates of the two lines shown above.

The only relevant holdings in the second case are KQx and KQxx onside and KQ doubleton offiside (x is any card available given the parameters above). KQxx onside occurs 4.783% of the time. This is reflected on the increased success rate of taking two finesses in the second case.

If you have information about the distribution of other suits, the calculations may be affected by the additional information.

[Jinksy]

broze, on 2015-January-19, 12:52, said:

At this point there are two relevant holdings:

xx - KQ and
Kxx - Q

right? The former holding is slightly more likely to have been dealt than the latter holding so you might reasonably think that it is right to go up with the Ace here. However, it is totally correct to play low. Why?

Because it is a restricted choice situation. RHO could have won either the K or Q from KQ tight so according to restricted choice he is more likely to have stiff queen and this offsets the fact that xx-KQ is (slightly) more likely to have been dealt a priori.

This is only true to the extent that you can rely on RHO playing randomly from KQ. Many weaker players would reliably play the lower honour in accordance with the general principles they've been taught, which I'm too tired to work out, but I think makes it about 50-50, all else being equal.

[PhantomSac]

They have to win the king such a small percentage of the time for hooking to be right, and even if you are right about them winning the q 100 percent of the time you gain such little edge, while losing a ton if you are wrong and they are close to random (or worse win the king more than the queen). It is not worth worrying about it even in a practical sense.