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A. Team competitions are typically scored using the International Match Points method (IMPs). Most bridge players like IMP scoring, since it gives proper reward for bidding and making game and slam contracts. Part score deals have fewer IMPs at stake, but the progressive IMP scale ensures that their significance is not lost. A method of scoring pairs competitions using IMPs was invented and promoted by the British Bridge League, under the chairmanship of Geoffrey Butler, some 50 years ago, and is usually referred to as the "Butler Scoring Method".
It is possible to use the IMP scoring system for pairs competitions. There is more than one method of doing so, but the simplest and most popular is the Butler method. For each board:
· A "datum" score is computed from the set of the scores by discarding the highest and lowest scores and retaining the rest. If there is more than one instance of the highest (or lowest) score, one of these is discarded and the other(s) retained. The datum is the arithmetic mean of all of the retained scores rounded to the nearest 10points.
· For each pair (including those pairs whose scores were discarded from the datum calculation), a net score is calculated by taking the pair's score for the board and subtracting the datum score. This score, positive or negative, is converted to IMPs according to the IMP table. Each of the pairs scores that number of IMPs for the board, one pair getting the positive score and the other the negative score.
This procedure is executed for every board, and each pair's total IMP score across all of the boards is computed. The winner is the pair with the overall highest total of IMPs. The Butler method can be applied to both single winner and two winner duplicate pairs movements.
Q. What are the advantages of the Butler scoring method?
A. Using the Butler Scoring Method makes it appropriate for pairs to employ essentially the same tactics that they would use in a IMP team competition. Namely:
· Overtricks are worth a maximum of 1 IMP each, and may possibly not gain anything (depending on the datum level). It is tactically unsound to risk going down in a contract that can be made safely in an attempt to score an overtrick.
· The 10 point premium for playing in no trump is insignificant at IMP scoring. Playing in 4 spades, scoring 420 points, will not lose to those playing in 3NT+1, scoring 430 points.
· Minor suit game contracts should be attempted whenever the 11 trick contract is safer than 3NT. You will tie with those making 9 tricks in 3NT (the same as when using MP scoring). The loss to those pairs making 10 tricks in 3NT will be small, unlike at MP scoring. On the other hand your gain, when the minor suit game makes and 3NT fails, will be huge.
· Pairs should be more prepared to bid close game contracts than they would be under MP scoring. A close vulnerable game contract will score, say, 620 when it succeeds and lose 100 when it fails.Compare that with the safe part-score of 170 or 140 and the gain is 620 - 170 =450 (+10 IMPs) when game succeeds (10 tricks) against a loss of 140 + 100 = 240(-6 IMPs) when it fails (9 tricks). You will come out ahead in the long run even if game succeeds only 40% of the time, since 40% of 10 IMPs is 4 IMPs but60% of -6 IMPs is only -3.6 IMPs.
The majority of bridge players find IMP scoring leads to a more interesting game of bridge. Playing Butler Scoring also has the advantage of giving club players practice at using the correct IMP tactics that will be necessary when they represent the club in a match.
Q. What is the difference between Match Points and Butler when it comes to scoring and tactics?
A. The type of scoring significantly affects a pair's (team's) tactics. For example, at matchpoints, making one more overtrick than everybody else on aboard gives the same result (the top) as making a slam that nobody else bid,whereas at IMP scoring, the difference comes down to 1 IMP (30 points) in the first case, but 11 or 13 IMPs (500 or 750 points) in the second case. In general, matchpoint scoring requires a more "vivid" and risk-taking approach, while IMP scoring requires a more cautious approach. The main features of the tactics are:
Matchpoints
· Overtricks are important
· Safety play is often neglected in the hunt for overtricks
· Thin games and slams are avoided
· Sacrifices are more frequent; e.g. going down 500 points on a doubled contract is a good result if the opponents can score 620 points for a game.
· Doubles are more frequent, as they increase the score for the penalty. For example, "the magic 200" refers to the situation when a pair beats the vulnerable opponents one trick doubled — the obtained score of 200 will likely outscore all partial contracts played on other tables.
· Playing in higher-scoring denominations (no-trump or major suits) is important, as it may lead to an extra 10 or 20 points.
· Due to the above,it is often unclear to the defense, and sometimes even to the offense, what their goals are. Thus mastering matchpoints play requires additional skills (sometimes referred to as "not bridge" by those who dislike it) to those required to playing IMPs.
IMPs
· Overtricks are not important, as it's not worth a significant risk of losing a game bonus of300–500 points = 8–11 IMPs (or to a lesser extent a part score of 110 to 190) for the potential 1-IMP gain for an overtrick.
· Safety play is very important, for the same reason.
· Thin games and slams are often bid. Bidding a game with 40 percent probability of success vulnerable and 45 percent non-vulnerable, or a small slam with 50 percent probability, is worth the risk, and anything over that increases the probability of a positive IMP score in the long run.
· Sacrifices are less frequent, as they may be risky.
· Doubles are less frequent, as they may be risky. Often, when an opponents' contract is doubled,it turns declarer's attention to the bad lie of cards, and may induce him to take a successful line of play that he wouldn't take otherwise.
· The contract itself sets a clear goal for both the defense and declarer, frequently allowing a deeper level of counter-plays between them.
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