Matchpoints, none vuln, playing 2/1 you hold:
♠ Qxx
♥ Kxx
♦ Kxx
♣ Q98x
Pard opens 1♣ and you bid a 7-10 1NT. LHO butts-in with 2♠, which gets passed round to you. You decide to compete with double (max hand, suggests penalty) and pard, for some strange reason, comes up with a 3♦ bid. Well, at least that marks his 4♦5♣ shape. You wonder what to do when RHO "rescues" you with a 3♠ bid and it's decision time. The auction so far was
Pard RHO you LHO
1♣...pass..1NT..2♠
pass.pass..dbl..pass
3♦.....3♠....??
Pard's bidding was weird, but he did say just about everything about his hand, so obviously you're the one who has to act. These particular opps are aggressive, so not all in the field will find the 2♠ overcall or the 3♠ raise. You pretty much have to double or bid 4♣. With such a defensive hand, the obvious choice is double.
But then I started wondering. "I don't think we can set them more than 1, so I seem to be fixed for a bottom unless I can make 4♣. Can I expect to make that? I got 10 hcp, and our side's short suit total (SST) is 4, so, if pard can cooperate with 12-13 working points (WP) we might be able to take 10 tricks. It is not unreasonable that he has those 12-13 WPs and I seem to be fixed anyway, so I might as well try 4♣."
And, against my better judgement, I bid 4♣. The hands turned out to be:
As you can see, pard had just about the best hand I could hope for and it STILL depends on the heart ace being onside. It was not to be. Opps cashed 2 spades and later came to two more hearts, the ace being offside. Not good, as -300 was available in 3♠ X (opps have mirrored shapes, but -100 would be about par).
So what happened here? Well, it turned out that 5 of my "working points" (♠Q, ♥K) were actually not working! We had 20 WPs and we came to 9 tricks, exactly as predicted by the FTL method, so the theoretical expectancy is completely fine. But I was unable to compute the expectancy at table. Sure, one could argue that my major suit honors should be discounted. But what if pard has, say, the ♠K or ♥Q? Well, one just doesn't know what the WP are.
The bottom line is while FTL is indeed quite precise in theory, in practice it is often too difficult to evaluate the WP expectancy. That is a serious drawback of the method. I'll keep experimenting, but right now FTL seems more useful to evaluate stuff after a splinter or fit bid than in a close competitive situation.

Help

s
t
r-m
nd
ing) tr. v. - Any bid made by bridge player with which partner disagrees.
West plays 4♣