IMP Pairs at Ipswich & Kesgrave

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Matchpoints and IMPs

We play matchpoint pairs every evening except two team competitions a year and the last week in months containing five Thursdays. On those fifth Thursdays for a little variation we play IMP pairs. There is now a club competition awarding a trophy to the best pair over the four IMP Pairs evenings played throughout the year.

In matchpoint pairs the rank of the scores is important, not the size. A pair's percentage at the end of the evening is the average of the percentage on each board. That percentage comes from how high each score is ranked, top to bottom. The size of the gaps makes no difference.

Team bridge is four-handed playing as two pairs, one East-West, one North-South. Played head-to-head, a team's score is the sum of its pairs' scores. Now the size of scores is important. Consider a team where NS make one fewer trick in the same contract than their EW concede to opponents.

• NS make 1NT exactly, their EW allow eight tricks, the sum is +90 plus -120, a net of -30.
• NS go one down in 1NT but their EW allow seven tricks; (non vul) is -50 plus -90, net -140.
• NS go down in 3NT but their EW allow nine tricks; -50 plus -400, net -450.
• NS go down in 6NT but their EW allow twelve tricks; -50 plus -990, net -1040.

To prevent a single board having a huge effect, say a grand slam or big penalty, the net scores are compressed by conversion to IMPs – International Match Points. The scale is printed on your personal scorecards. For the examples above the IMPs are -1, -4, -10, -14

At IMP scoring size matters.

Why Play IMP Pairs?

When clubs organise team events, players must either form themselves into teams, maybe taking pot-luck with another pair who also arrive without teammates or submit to a random draw. Some of these options are unpopular with players who either do not want to depend on a pair they don't know for their evening's result or are uncomfortable with having another pair depending upon them

IMP Pairs Scoring

For each board, each pair's score is converted to IMPs as if each pair in the opposite direction (other than those faced) were the pair's teammates. The score carried forward to the end of the evening is the average of those IMP conversions (including fractions). Those are summed for the final pair scores.

This method is known as Cross-IMPs; it is very common online and, even for our team games, each pair's score for the national Grading System (NGS) is calculated this way.

Team Tactics

Unlike matchpoint scoring, at IMP scoring not every board counts the same. In the example scores above, making/defeating contracts is important; games, slams and sacrifices are 'big' boards, part-scores less so.

Since IMP Pairs is at heart a team game, you need to adopt team-tactics in bidding and play to do well. Here are a few tips you and your partner might like to consider.

• Overtricks are relatively unimportant; never risk the contract for an extra trick.
• The same is true of extra undertricks; never risk a contract making by trying to defeat it by two (or more) tricks when you can simply take it one down.
• The reward for bidding and making games is considerable. Bid games that might be slightly against the odds, especially when you are vulnerable when the reward is higher.
• Seek safety: prefer a safe 5 over a risky 3NT, prefer a safe 2 over a risky 1NT. The gains from higher-scoring no-trumps do not offset the losses when it goes down.
• Always play in the safest slam: 6 making is better than any risks in 6NT.
• Be wary of doubling part-scores of 2 and above – 'doubling into game'. If they make the contract, they get the game bonus, essentially on a part-score deal.
• Plus-scores are good. Be wary of over-competing part-scores; accepting +100 instead of +110/140 is no loss (or only 1 IMP), whereas conceding -100 instead of taking +100 is a loss of five. Defeating their low-level contracts and making yours ensures a useful supply of IMPs on boards that you might regard as 'dull'.
• Don't prolong the play when your contract is assured – save your time for the next critical deal.