The odds associated with a finesse are traditionally 50-50, but sometimes you can achieve a 100% result by finessing into the safe hand — and sometimes you can achieve an equally good result by rejecting the finesse altogether.

Consider today’s deal, in which you reach what appears to be the normal contract of four spades, on a passive club lead from West.

To digress for a moment: I would certainly lead a red-suit against that contract myself, since it is far more likely that you need to set up winners than go passive here, but that is another column. Similarly, the question of whether to lead second-highest from four small here would produce different opinions from different players.

You win the club ace and hasten to draw trumps; what next? You should cash the club king and ruff a club to eliminate that suit altogether. Now you must play the diamond ace followed by the diamond queen. Yes, you give up on the finesse, but you have ensured your contract in the process. Whoever wins the diamond king must give you a trick in return, either via a ruff-sluff or by broaching hearts for you, to ensure that you lose no more than two tricks in the suit.

Note that if you take the diamond finesse, you risk going down. When it loses, back comes a diamond, and you will find you still have to lose three hearts.

The technique here, of eliminating the side suits and forcing a favorable return, is one worth adding to your repertoire.

Today’s deal comes from the 1989 European Championship and was declared by Tony Forrester, who played in four hearts on the spade 10 lead. Forrester has been ever present on the Great Britain and now England teams over the last 35 years. He is well known as being both a tough opponent to play against because of his imaginative and aggressive bidding, and also for being an excellent technician.

The contract of four hearts seemed reasonable, but when the spade 10 was led, the risk of a ruff on defense suddenly became a serious one.

If declarer were to win the opening lead and try to draw trumps, the defense would score their ruff, play off their top trumps, then exit in clubs. They would eventually collect a diamond winner.

Forrester had other ideas; he won the opening lead, played the club ace and king, then ruffed a club in hand before playing the heart jack. East won the heart ace and returned a spade. The good news was that his partner could ruff and cash the heart king, but after that, he was endplayed. With only minor-suit cards left, he could exit in diamonds into the tenace or play a club, at which point declarer would pitch dummy’s diamond loser(s) and take the rest via his top spades, the diamond ace, and the three trumps.

This deal emphasizes how often, when you need cooperation from your opponents, eliminating the side suits early can put additional pressure on the defenders, sometimes in unexpected ways.

There are advantages to being a pack rat (though it is possible my wife would not agree). Going back through my copious records, I discovered a deal from a national tournament of the 1970s.

The deal arose in the Spingold Trophy, where both tables declared four hearts. After the lead of the club jack to the king, East cashed the club ace and erred by playing a third club. That gave declarer a chance by allowing him to try to shorten his trumps and cope with a bad break. A diamond shift would have left declarer no chance as the cards lay.

Robert Lebi, then of Montreal, earned a 12-IMP swing for his team by ruffing and playing a heart to the ace. Believing East’s king was a true card (who would find the false card here?), he cashed the spade ace, ruffed a spade and took the diamond ace and king, before ruffing a diamond to dummy. After ruffing a spade to hand, declarer was down to the heart Q-10 and the diamond jack, while West had been forced to follow suit throughout and held J-9-3 of hearts. The diamond jack completed the coup: West ruffed and had to lead into the trump tenace.

The Lebi team won their knockout match by 11 IMPs when the other declarer was given the same chance at trick three but did not ruff a spade when in dummy with the heart ace!

For the record, in almost every variation, a diamond shift at trick two from East is either essential or at least as good as a club.

When a partnership has the Jacoby two no-trump available for slam-interested raises of partner’s major, the initial splinter jump tends to need partner to have real extras — or a perfect fit — to consider slam. In this case, when North jumps to four hearts (a splinter bid for this pair, not a natural jump), South has a highly suitable heart holding but a dead minimum, so he signs off in game.

On the lead of the heart queen, South should try to develop dummy’s clubs, but he can still fall back on a successful finesse in diamonds. So, he wins the first trick with the heart ace and draws trumps, ending in dummy.

South begins the clubs by leading toward the king, on which East alertly unblocks his jack. South takes his king, then leads a low club toward dummy. Since one club trick must be lost no matter what happens, declarer hopes to duck this trick to East. But whether he wins or ducks the second club, West will get in with his clubs and must then lead the diamond queen. He needs to hope his partner has the A-J-10, or that declarer will be unable to guess what to do with the cards lying as they do today.

If South ducks the queen (playing West for the Q-J-9), he is done for. But he should not do that, since West would probably have led a diamond at trick one with that holding. If South covers the queen, East should take his ace and return a low diamond. I don’t envy declarer his decision now!

When is a finesse not a 50-50 chance? When you take a finesse, your odds of success can vary enormously, depending on what you know about the rest of the deal, but you can tilt the odds in your favor sometimes by making the opponents lead the suit in which you need to take the finesse.

Today’s deal shows a hand that appears to depend on the diamond finesse, but you can sway the odds in your favor — and in some cases, avoid the diamond finesse altogether. In other cases, you can turn a 50 percent chance into something much better.

Against six hearts (reached after an insouciant but practical jump to slam), you capture the spade king with your ace and draw trumps, ruffing dummy’s spades in hand en route. The best sequence of plays may be to take two rounds of trumps, then the club ace-king, followed by a spade ruff, a third trump to dummy and a second spade ruff.

Now you lead the club nine from hand and concede the trick that has to be lost, hoping the defenders will give you something in return. If East wins the club, you are safe against any return. If West wins, he must lead a diamond, and you simply cover his card.

The slam will come home if West has either the queen or both the 10 and nine, since you will be able to take two finesses against those cards. In other words, careful play has improved your chances in the slam from one in two to something closer to two in three.

Gone are the days when South would buy the hand in two spades here. West’s shape outweighs his minimum values when it comes to protecting; if the opponents stop in two spades, he must balance and try to push them up or find a making part-score for his side. Similarly, North’s fourth trump persuades him take the push to three spades; then it is up to South to justify his partner’s confidence in him.

Declarer ducks the opening club lead, wins the next club in dummy with the ace and takes the trump ace and king, then ruffs a club to dummy and leads a heart to hand.

Since West has short spades, South assumes he must have a three-suited hand with no other shortage. Equally, though, he cannot have both missing top diamonds, or he would have doubled one spade.

South must hope East does not have the diamond queen. With no other information to go on, declarer might have led a diamond to the 10, but not today, since West surely cannot hold precisely a doubleton diamond queen. Instead, South leads the diamond jack from his hand. West must cover, or declarer will be out of the woods. Declarer puts up the king, and East takes his ace, then cashes his master trump and plays on hearts. South ruffs the third round and must now bring in all the remaining diamonds to make his game.

Since West has diamond length, it must be right now to lead a diamond to the eight, finessing against the nine. When the finesse succeeds, declarer is home.

Today’s deal sees North with enough values to drive to game facing a one-heart opening bid. Since he has a full opener and primary heart support, he starts by responding two diamonds, then jumps to four hearts to suggest a minimum game force and no slam interest.

Digressing for a moment, these aren’t my preferred methods. I’d like a jump to four hearts to be concentrated in the red suits with no controls in the black suits — but that isn’t a majority style.

Anyway, all routes lead to four hearts, and declarer should probably duck the initial spade lead, hoping to cut the defenders’ communications in spades if the suit is originally 5-2. He wins the next spade and plays a diamond to the king. When West gives count in diamonds East ducks the first round of that suit. Declarer now draws trumps in three rounds, then leads a second diamond. Regardless of which diamond declarer plays from dummy, East wins cheaply and returns a club. That lets declarer win in hand and play a third diamond. Now, since East has no spades left to lead, he must concede the rest after winning his second diamond trick.

If declarer makes the mistake of winning the first trick, the defenders will come to four tricks sooner or later. While there are lies of the cards where winning the first trick is necessary, they are few and far between: An original 5-2 spade break with the diamond honors misplaced is far more likely than that.

When North raises his partner’s spades, South does not want to commit the hand to four spades without contemplating three no-trump first. He bids three clubs in the hope that his partner can bid three no-trump, then raises himself to four spades when North signs off. It would be too hard to land on the head of a pin and pass three spades.

The defenders have no reason to do anything but lead three rounds of diamonds. Cover up the East-West cards and decide how you would play the hand as South.

It certainly looks as if you can play on clubs via a finesse or perhaps try to duck a club to West, and force a favorable lead from him. However, even if the club king is offside, which you expect from the fact that West made a simple overcall rather than a weak jump, you have excellent chances for 10 tricks, as long as you are careful.

You ruff the third diamond and play the ace and king of trumps, planning to eliminate hearts and throw West in with the fourth diamond if trumps break. When they do not, you ruff out the heart and play the spade queen. If West comes down to just one diamond and three clubs, you endplay him with the fourth diamond, pitching a club from hand. If he keeps two diamonds and two clubs, you play the ace and another club, and your hand is high.

The defense can prevail, but only if East ruffs the second round of diamonds to play clubs — and who would do that?