This particular coup was discovered by Tom Oag while a player at Durham University Bridge Club. When I say discovered, what I actually mean is that it was discovered to work very well against Tom. This particular coup is 100% legal and is probably well known to all top players who have the privilege of playing against weak players on a regular basis at their local bridge club.
Suppose you have to play the following suit combination for no losers:
A J 9 5 | ||
K 10 7 3 |
Clearly, you could take the finesse either way, but there is an obvious way to play the hand if you have a 'Tom' sitting at your table. Let's say he is sitting on your right: play the jack from dummy. If right hand opponent has the queen, he will play it more or less 100% of the time, and you have four tricks. Should he not have the queen then naturally you play the king over your jack and finesse the other way.
Now I don't think we've suggested anything in this so far that appears controversial. After all, given the above layout, it might not be obvious to an average player that it's wrong to cover the jack — especially if they cannot pause for thought before playing to the trick, thus giving the position away. But the strength of the Tom coup is that it works, even when it really shouldn't. For example suppose the layout is as follows:
A J 10 5 | ||
K 9 6 2 |
It is now obviously wrong to cover the jack with the queen, and against a good player the in-tempo duck from right hand opponent should tell you very little about the correct way to play the suit. However — and this is where many good players really do fail to get the most out of their weak opponents — against a 'Tom' there is no reason at all to let the jack run; it is obviously correct to overtake the jack with the king and take the finesse against west as it is he who almost certainly holds the queen. True, you cannot now pick up a 4-1 with west; however, in comparison with picking up the suit about 90% of the time when it is 3-2, it is well worth this downside.
Finesse or Drop
With a nine card suit headed by the Ace-King it is a well known fact that it is playing with the odds to play to drop the queen rather than taking a finesse. This is all well and good if you have no other information. However, there is almost always more information available, and some very powerful information can be provided by this month's powerful coup. Look at the following two combinations and then see if you can use the Tom coup to give you the best chance of taking all five tricks:
On hand (a) you play the jack from hand and if the queen doesn't appear, you rise with the ace and hope to crash the queen in the usual way. In hand (b) the best play is to decide which of the two opponents is the biggest 'Tom' and play either the Jack from hand or the Ten from dummy. If your card is covered then all well and good, while if it is not covered you simply overtake the card and play low intending to finesse should the queen not appear from the hand that almost certainly holds it.
a) | A K 10 6 3 | |
J 7 5 2 |
b) | A 10 9 5 | |
K J 8 7 3 |
To use this powerful bridge tool you will have to make an assessment as to the standard of play of your opponents and then play accordingly. When playing in a mixed ability field, this is an essential part of achieving very high average scores. We at poorbridge.com (a) have absolutely no qualms about arrogantly thinking that our opponents are weak enough to fall for these little tricks and (b) think that this is totally a part of the game, in the same way as spotting a double squeeze or psyching a 1
opening is part of the game. Good luck with this one!

Note
The author would like to make it clear that all references to Tom Oag relate entirely to his bridge playing habit of always covering dummy's card if he possibly can. He is a nice bloke and maybe, should he ever read this article, he might drop the poorbridge team an e-mail and say hi!