# BBO Discussion Forums: Bidding question - BBO Discussion Forums

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## Bidding question Double Dummy Interpretation

### #1Trumantwo

• Group: Members
• Posts: 2
• Joined: 2019-October-25

Posted 2021-June-22, 09:09

I would like to know how I use the double dummy feature to evaluate my play on a board. I see notations of "=" and perhaps a dot containing '1' or '2'indicated on cards within a suit. How does this relate to my what is possible on a particular contract.
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### #2Stephen Tu

• Posts: 3,912
• Joined: 2003-May-14

Posted 2021-June-22, 09:36

"=" means playing any of the cards marked as such will lead to the bid contract making exactly if everyone plays optimally double dummy afterwards. A green "1" or whatever number signifies overtricks. A red number signifies undertricks, how much the contract will fail by. If you play a card and someone subsequently makes a double dummy error then the evaluation will change.

Keep in mind that optimal double dummy play often does NOT equate to optimal single dummy play. For example double dummy play might suggest that you are supposed to drop a doubleton q offside, whereas the percentage single dummy play on the hand might be clearly to finesse and lose to it. Or sometimes best single dummy play might require say an elimination and a throw-in to avoid a two-way finesse for a queen. Whereas double dummy you can just finesse the right way without the endplay.

So keep in mind it's *how* one *could* score the most tricks, not that you necessary *should* score the most tricks or play a suggested card. Analyze how the play should go with some key honors in the opp's hand swapped, and/or certain suits splitting/not splitting to evaluate how accurate your play is. Compare your line with known good players playing the same board if comparisons available.
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