OliverC's Precision Parlour        Guest User

When is a bid Sigma?

Sigma occurs only immediately after a positive response to an Alpha Ask:

• After a 3 or 4-step response to Alpha: A repeast Ask in the agreed trump suit below game level is Sigma, eg: 1♣-1♥-1♠-2♥-2♠ is Sigma in Spades. Similarly 1♣-2♦-3♣-3♠-4♣ is Sigma in Clubs.
  
• After a 5-step or greater response to Alpha: Here a relay in the next bid up is Sigma, eg: 1♣-1♥-1♠-2♠-2NT is Sigma in Spades, and similarly 1♣-2♦-3♣-4♦-4♥ is Sigma in Clubs.
  

There are no other situations where a bid can be Sigma. Also Note that Sigma (and Repeat Sigmas - see below) takes precedence over 4♣/4♦ Beta and a Relay Beta, but the Relay Beta is just displaced by one step, excluding the agreed trump suit and, if a Minor suit is agreed, excluding No Trumps. In practice there is not normally any conflict between Sigma and the Relay Beta, since the Relay Beta is never in the agreed Trump suit and Sigma always is. It is Repeat Sigma's that have to be taken into account when deciding "where" the Relay Beta is. Moreover a Relay beta is still available over the response to a Repeat Sigma.

Responses to Sigma

There are 3 different scales for Sigma depending on whether Responder has gone 3, 4, or 5+ Steps in response to the original Alpha Ask. This is because the minimum or maximum possible holdings are different for each. In practice, the 3 and 4-step scales are identical except that the higher responses to Sigma cannot occur over a 4-step response (because otherwise Responder would have gone 5+ steps in response to the original Alpha).

• After a 3-step Response to Alpha
  1. : xxxx(x)
  2. : Hxx
  3. : HHx
  4. : Hxxx(x)
  5. : HHxx(x)
• After a 4-step Response to Alpha
  1. : xxxx(x)
  2. : Hxx
  3. : HHx
• After a 5-step or greater response to Alpha
  1. : Hxxx
  2. : Hxxxx
  3. : HHxx
  4. : HHxxx
  5. : HHHx(x)

Repeat Sigma Asks

If Responder shows no Top Honours or only 1 Top Honour in response to Sigma, then a relay in the immediate next suit up (taking precedence over a Relay Beta) is allowed to check for possession of the Jack. eg: 1♣-1♥-1♠-2♥-2♠-3♣-3♦ is a repeat Sigma asking if Responder has the Jack of Spades. This might be a situation where Opener has K10xxx in Spades and wants to check further for trump solidity (ie: there is a big difference between Responder having Qxx and QJx, or Axx and AJx.

Notes

• Sigma should be used sparingly as very often the bidding space is better used in other ways, and very often responder's trump holding can be ascertained by a process of elimination by making Epsilon Asks elsewhere. The time when Sigma is normally found is when the Alpha-bidder has a relatively poor trump suit such as Hxxxx but otherwise a very strong solid hand not needing to ask many (or any) Epsilon Asks..
• This Asking Bid is new as of August 2007 and the Responses and Scales are subject to change if we decide that alterations are merited after we've used the Ask for a while. One area that might be changed is whether to simplify the responses but to incorporate posession of the Jack into the original Sigma responses.