[kmbirds]

I am new to BBO and don't quite understand how the IMP's are calculated. Are they cumulative for your game? Is the comparison done for all people who have played that hand? I am just playing relaxed bridge with IMP's calculated.
Thanks!

[awm]

For each board you have played, IMPs are calculated against each other pair that played the same board. These are then averaged. This is your IMP score for that board, which will appear in your results if you look at them. Note that the IMPs for a board can change after you play it, as other people play the same hand. In an extreme case, if you are the first to play the board your IMP score for that board will be 0 (no comparisons) but as soon as another pair plays it your score can change dramatically. The individual IMP scores are always integer, but the averaging can produce fractional scores.

The total IMP score displayed on the lower left of the screen is the sum of your side's (EW or NS) IMP scores on all boards played at this table since the host last reset the score. For this reason some people like to ask the host to reset the table score when they first sit down (of course, this is automatic if it's a brand new table). Of course, "My Results" just lists IMP scores for hands you personally played, so you can see how you are doing by looking there if the table score started before you sat down.

If you look at "My Hands" it lists the IMP scores for all boards which you have personally played and which have been played a full 16 times (so if a board has not been "finished" yet your score will not display for that board).

[kmbirds]

Thanks! Nice description.