What Are IMPs in Bridge?
IMPs (International Match Points) are the scoring units used in team bridge: the raw point difference between your table and the other table on the same board is converted to IMPs on a fixed scale that runs from 0 to 24. Jump to the full bridge IMP scale below, or convert any result with the bridge score calculator.
Two Scoring Systems, Two Different Games
Bridge is played under two main scoring formats: matchpoints (MP) and International Match Points (IMPs). The format you are playing dramatically changes how you should bid, play, and defend. A decision that is brilliant at matchpoints can be a blunder at IMPs, and vice versa.
Understanding both formats is essential for any competitive bridge player. Most club games use matchpoints, while team events and online challenges often use IMPs.
How Matchpoint Scoring Works
In matchpoints, your result on each board is compared to every other pair who played the same hand. You get one matchpoint for each pair you beat and half a matchpoint for each pair you tie. Your final score is a percentage of the maximum possible matchpoints.
This means every overtrick matters. Not vulnerable, making 4 Spades with an overtrick (450) scores better than making 4 Spades exactly (420), even though both are "making game." At matchpoints, that 30-point edge is as valuable as a 1000-point edge - you still beat exactly one pair. To check how any contract, overtrick, or penalty scores, use the bridge score calculator.
How IMP Scoring Works
In IMP scoring, your result is compared to one other team. The difference in total points is converted to IMPs on a logarithmic scale. Small differences (under 20 points) convert to 0 IMPs, while large swings (500+ points) produce big IMP gains.
This makes game and slam bonuses extremely important. The IMP scale rewards bidding and making close games: bidding 4 Hearts making versus stopping in 3 Hearts is worth around 6 IMPs. But overtricks barely matter - one overtrick in 4 Hearts is worth only 1 IMP.
The IMP Scale: How Points Convert to IMPs
IMPs come from a fixed conversion scale set by the World Bridge Federation. You first find the raw point difference between the two tables, then look up how many IMPs that difference is worth. The scale is deliberately compressed: doubling the points does not double the IMPs.
The key steps run like this. A difference of 20 to 40 points is worth 1 IMP; 50 to 80 is 2 IMPs; 90 to 120 is 3; 130 to 160 is 4; 170 to 210 is 5; 220 to 260 is 6; 370 to 420 is 9; 430 to 490 is 10. From there it keeps slowing: 500 to 590 is 11 IMPs, 750 to 890 is 13, 1100 to 1290 is 15, and it tops out at 24 IMPs for any difference of 4000 or more.
Two lessons fall out of the scale. First, small differences vanish: winning a partscore battle by 20 or 30 points is only 1 IMP, so overtricks barely matter. Second, the game and slam bonuses create big jumps, which is why bidding a thin but making game (about 10 IMPs swing versus stopping short) is worth the risk at IMPs but not always at matchpoints. The full scale is in the table below; the bridge score calculator applies it for you when you compare two results.
| Point difference | IMPs |
|---|---|
| 0 - 10 | 0 |
| 20 - 40 | 1 |
| 50 - 80 | 2 |
| 90 - 120 | 3 |
| 130 - 160 | 4 |
| 170 - 210 | 5 |
| 220 - 260 | 6 |
| 270 - 310 | 7 |
| 320 - 360 | 8 |
| 370 - 420 | 9 |
| 430 - 490 | 10 |
| 500 - 590 | 11 |
| 600 - 740 | 12 |
| 750 - 890 | 13 |
| 900 - 1090 | 14 |
| 1100 - 1290 | 15 |
| 1300 - 1490 | 16 |
| 1500 - 1740 | 17 |
| 1750 - 1990 | 18 |
| 2000 - 2240 | 19 |
| 2250 - 2490 | 20 |
| 2500 - 2990 | 21 |
| 3000 - 3490 | 22 |
| 3500 - 3990 | 23 |
| 4000 and up | 24 |
How Strategy Changes by Format
At matchpoints, play safe lines that maximize your expected number of tricks. Go for overtricks when you can do so without risking the contract. Choose the opening lead that beats the most results, even if it occasionally gives away a trick. The bridge odds tables show the suit-break and hand-pattern frequencies behind these percentage decisions, and the opening leads guide covers how the format shifts your lead choice.
At IMPs, play to make your contract above all else. A 50% game is worth bidding. Take the safe line for your contract rather than risking it for an overtrick. On opening leads, choose the lead most likely to defeat the contract, even if it sometimes gives away an overtrick.
A useful rule of thumb: at matchpoints, think about frequency (how often does this work?). At IMPs, think about magnitude (how big is the swing when this fails?).
Which Format Should You Practice?
Both. Playing matchpoints sharpens your competitive edge and forces precise play, while IMP practice builds judgment for team games and helps you learn when to bid aggressively. BridgeDummy offers both MP and IMP puzzles so you can train each skill independently.