7.2.3 Taking SacrificesNow we’ll look at the difference betwen IMP and MP tactics when it comes to close decisions to bid game. It all comes down to assessing how much you are risking and how much you might gain by pushing on to game.
At IMPs, if you bid game and go down, you lose the cost of the down trick, and the value of the partscore you could have made. If you stay in a partscore and make game, you lose the difference in value between the game bonus (300 or 500) and the part-score bonus (50). Of course these total point values are converted to IMPs.
At MPs, if you bid game and go down, you lose one matchpoint to every pair that stayed in the partscore, regardless of how many tricks they made, and if you bid it and make, you gain one matchpoint for every pair that stayed in a partscore, and half a matchpoint for the scores you tie. How many tricks you take will also affect your matchpoint score, but that is usually the case whether you bid game or not, especially on the close decisions.
Let’s look at a simple example, suppose your game will make if a finesse is onside, and go down if it is offside. The deciding factor in whether or not you should bid the game at IMPs is whether or not you are vulnerable. This example assumes you are playing a head-on match against one team, but the scoring at IMP pairs (Lehmans or OKBridge Tourneys) will usually work out to about the same. We will look at what happens when you play a partscore and the opponents play game.
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So, not vulnerable, if your game doesn’t need any more than a finesse to make, in the long term, you will about break even by bidding game or passing.
Vulnerable, if your game doesn’t need any more than a finesse to make, in the long term, you will be far ahead by bidding a game. In fact, you need to make less than 40% of the vulnerable games you bid to break even.
How do we work this out? Assume you have to make the decision ten times, and being greedy like me you go for all ten. If 4 of them make, you will win 4 times 10 for 40 IMPs, and on the 6 that go down you will lose 6 times 6 for -36 IMPs!
I often hear people using the excuse of “Well I wasn’t vulnerable” for an overbid. Actually, if you are playing IMPs, you are better off being pushy when you are vulnerable than when you are not.
When it comes to match points, since the size of the difference in score with your opponents doesn’t matter, you just need to be right. If game makes, bid it, and if it doesn’t, pass.
Not very practical advice you say? Well it comes down to this: You want your games at MP scoring to be a little better than even odds. Often you can get a decent score just by taking the extra trick, even if you don’t bid the game.
Suppose superior declarer play or inferior defense will let you make 10 tricks in a major. Here might be a sample of scores in an 8-table game at MP.
| Table | Contract | By | Result | NS+ | NS- | MP Score |
|---|---|---|---|---|---|---|
| 1 | 4♠ | N | = | 420 | 6.5 | |
| 2 | 4♠ | N | = | 420 | 6.5 | |
| 3 | 3♠ | N | +1 | 170 | 5.0 | |
| 4 | 3♠ | N | = | 140 | 3.0 | |
| 5 | 3♠ | N | = | 140 | 3.0 | |
| 6 | 3♠ | N | = | 140 | 3.0 | |
| 7 | 4♠ | N | -1 | 50 | 0.5 | |
| 8 | 4♠ | N | -1 | 50 | 0.5 |
So, if you don’t bid the pushy game, but still get 10 tricks, you get 5 out of a possible 7 MPs, for 71% of the match points, but if you bid the pushy game and take only 9 tricks, you get 0.5 out of 7 MPs, for 7%. Another way to look at it is that you are risking 5 MPs (your score for making 10 tricks without bidding game) to gain 1.5 (your score for bidding and making game). Obviously not a good proposition! Whether you are vulnerable or not doesn’t affect the decision at MPs.
| 7.2.1 Part Score Battles |
7.2.3 Taking Sacrifices |