DOPI is a defense used after interference over ace-asking slam bidding conventions such as Blackwood and Roman Keycard Blackwood. It uses the Double and Pass bids as responses to enable you to answer partner’s query even when bidding space is restricted.
DOPI stands for “Double = 0, Pass =1” and serves as a good reminder of how you should bid after interference over 4NT ace-asking bid. This convention is often used alongside ROPI, which uses similar bids to communicate after opponents double the 4NT bid.
How to Use DOPI
| Response | Meaning |
|---|---|
| Double | 0 aces |
| Pass | 1 ace |
| Cheapest Bid | 2 aces |
| Second-Cheapest Bid | 3 aces |
| Third-Cheapest Bid | 4 aces |
For example, in the hypothetical sequence 1♥ – (2♣) – 3♥ – (4♣) – 4NT – (5♣), where 4NT is Blackwood, a hand with 0 aces would double, with 1 ace pass, 2 aces bid 5♦, etc.
This same system can be used if Roman Key Card Blackwood is interrupted. Here are the responses for 3014 RKCB:
| Response | Meaning |
|---|---|
| Double | 0 or 3 keycards |
| Pass | 1 or 4 keycards |
| Cheapest Bid | 2 key cards without the Q of trumps |
| Second-Cheapest Bid | 2 key cards with the Q of trumps |
As you’d expect, the responses are switched round for 1430 RKCB:
| Response | Meaning |
|---|---|
| Double | 1 or 4 keycards |
| Pass | 0 or 3 keycards |
| Cheapest Bid | 2 key cards without the Q of trumps |
| Second-Cheapest Bid | 2 key cards with the Q of trumps |
Opponent Doubled? Try ROPI
ROPI, “Redouble = 0, Pass = 1”, is used in those situations where the opponent’s double your 4NT ace-ask instead of overcalling it.
The responses are pretty self-explanatory so we’ll only repeat them for Blackwood – you can probably figure out the RKCB equivalent:
| Response | Meaning |
|---|---|
| Redouble | 0 aces |
| Pass | 1 ace |
| Cheapest Bid | 2 aces |
| Second-Cheapest Bid | 3 aces |
| Third-Cheapest Bid | 4 aces |
The One Small Problem With DOPI You Should Know About
When the opponent’s intervene above the 5th level of your suit DOPI you start to run out of bidding space. Consider the following auction:
1♠ – (3♥) – 4NT – (6♥) – ?
Using DOPI, two of the responses push you past 6♠. Even if the opponent’s intervene at the 5th level, if their suit is ranked higher than yours you have precious little bidding room.
The solution is DEPO (or its cousin, DOPE), which we’ll look at in the next section.
DEPO & DOPE
DEPO stands for “Double = Even, Pass = Odd” and is a simpler alternative to DOPI. The benefit of using it is that it is much simpler and doesn’t use any bidding space, so it can be used even when opponent’s bid too high for DOPI.
The responses are simple:
| Response | Meaning |
|---|---|
| Double | Even number of aces (or keycards) |
| Pass | Odd number of aces (or keycards) |
DOPE, or “Double = Odd, Pass = Even”, swaps these responses round:
| Response | Meaning |
|---|---|
| Double | Odd number of aces (or keycards) |
| Pass | Even number of aces (or keycards) |
Of course, you do lose the ability to communicate so much information. For this reason, some partnerships play both DOPI and DOPE, with an agreement that DOPI is standard but they use DOPE if the opponent’s bid above a pre-determined level. This works well as long as the partnership both remember which one they are playing!
We Want To Hear From You
- Which ace-asking bids do you use when exploring slam?
- Do you play DOPI or DEPO with them? Or both?
