[maryob713]

In a casual game on the left side of the screen there is a box the shows IMP NS and EW. It has numbers + for one and - for the other. What do these numbers have to do with the hand being bid and played?

[mycroft]

Nothing at all. It's a running tally of (cross-)IMPs scored on previous hands since they were last cleared.

If cross-IMPs is new to you, it's how IMP pair games are scored:

• each hand is played "16" times
  
• each N-S result is compared against each of the other tables' E-W scores, and converted to IMPs
  
• the total is divided by the number of comparisons, and that's N-S score on that hand (E-W gets the opposite).

16 is in quotes, because:

• your table is usually not the last time the board is played, and the scores are updated on the fly as new results come in (the IMP score on the left side of the screen is updated every hand, not on the fly)
  
• some hands fall off and aren't played the maximum 16 times.

[gbb483]

You'll also notice that when you've made a particularly difficult contract, using an ingenious play, the running score doesn't change. Then when you check on 'other tables' you discover noone else has played the hand. In fact you've usually managed to play 3 or 4 more boards and forgotten the hand before anyone else plays it, and when your running score jumps you incorrectly attribute it to the last board played.

It also begs the question - is the EW score ever other than the inverse of the NS score? If not, why bother showing both?

[Vampyr]

gbb483, on 2020-August-09, 09:30, said:

You'll also notice that when you've made a particularly difficult contract, using an ingenious play, the running score doesn't change. Then when you check on 'other tables' you discover noone else has played the hand. In fact you've usually managed to play 3 or 4 more boards and forgotten the hand before anyone else plays it, and when your running score jumps you incorrectly attribute it to the last board played.

It also begs the question - is the EW score ever other than the inverse of the NS score? If not, why bother showing both?

It does not “beg the question” but in any case you can check the history to find out what you scored on each board.

[barmar]

gbb483, on 2020-August-09, 09:30, said:

It also begs the question - is the EW score ever other than the inverse of the NS score? If not, why bother showing both?

I've been wondering that for many years, but I've never been able to convince others here that they're redundant.

[mycroft]

There are way too many people, most of them E-W (because most of them "don't want to use the machine"), who wouldn't figure that out.

"So, if they get 3, we get -3? Isn't it just 3 in the they column?"

I don't know why - it should be obvious on first explanation. But it's something that I have seen repeatedly as a stumbling block that is really difficult to clear.

[barmar]

On personal score sheets for team games, it's pretty common to have separate columns for We and They, so it actually makes sense to copy this. It's easier to distinguish all the positive and negative scores when they're separated.

Where it becomes less useful is in Matchpoint games. I don't need to see both We=64% and They=36%.

[Vampyr]

barmar, on 2020-August-17, 16:28, said:

On personal score sheets for team games, it's pretty common to have separate columns for We and They, so it actually makes sense to copy this. It's easier to distinguish all the positive and negative scores when they're separated.

Where it becomes less useful is in Matchpoint games. I don't need to see both We=64% and They=36%.

It’s strange when you view the other table in a match; the We and They are backwards. NS and EW would be a clearer way to designate the columns.