Posted 2017-September-21, 18:39
So I think the two basic lines are very close and it wasn't clear in my mind which was ahead until I made a fairly exhaustive calculation, my teammates were quite unsure.
The two plausible lines are:
1. Try the ten, if covered, SA, then something like s8 to s9 or ST to SJ (if someone has Kxxx and decides to duck, you want to be in dummy to take the diamond hook)
If spades are 4-1, presumably a club comes back, cross in trumps and take the diamond hook. If it wins draw trumps and claim. If it loses and the opps maneuver diamond or heart ruff you are down. If not you have a second chance diamond hook.
2. High heart from dummy, to be assured you can take the spade finesse, try running the s9, repeat if wins.
I made the assumption that LHO would not falsecard on lead, and the methods at the 2 tables happened to be 3rd/low at one table, and Polish style 2/4 at the other, so the idea is that unlike with 4th best leads combined with non-MUD, you don't have to end up guessing if LHO had 3 small or 4 to the J as different cards are led. The magnitude of the calculations differed depending on which style was on lead. I also ignored overtrick/undertrick calculations
If spades are 3-2, the only time you can really go down is if both DKJ are offside. Line 1 gains if the SK is offside, and the lead was singleton or doubleton, so you get your 4 heart tricks. Line 2 gains if RHO has Kx doubleton of spades and gives LHO the heart ruff. But if spades are 3-2 LHO/RHO, it's 3:2 that the SK is offside. So this favors line 1.
If spades are 4-1, line 1 tends to gain if the SK is stiff by guaranteeing the 4 heart tricks (when rest of hand is unfriendly), and when LHO has 4 to the K (extra heart trick some times, extra entry to dummy to take a second diamond hook if can avoid heart ruff)
The big gain for line 2 is when spades are 4-1 with RHO having Kxxx, here you both pick up the spades and often still have 4 heart tricks. Line 1, you will need DK onside, or at least one of DK/DJ onside and avoid heart or diamond ruff.
finessing also gives some extra chances of making if 5-0 onside (e.g. 3+ hearts and DK onside)
Both lines have high success rate, but my calculations, if I didn't screw up, showed 1-2.5% making advantage for the HT line, depending on the lead agreement (lower advantage vs. 2/4).