The S1-Scheme includes all the 1-suiter shapes and those 4441 shapes with both minors (i.e. with a Major shortage).

On entry into the S1-Scheme one suit is always known: the long suit if 1-suited or the 4-card Major if 3-suited (with both minors).

The S1-Scheme is entered by first showing the long suit (as mentioned above) if , or and then bidding the S1-key of 2. A direct bid to 2 infers long clubs.

The S1-Scheme hand shapes are divided into two lists:

• The Main 1-suiter list: M1 = 5332, 6331, 7321, 7330,…

• The Equal Residue list: E1 = 4333, 4441, 7222

The remaining 6322 shape is handled separately.

After identifying the long suit, the base-level for the S1-Scheme shape responses is 2.

The S1-Scheme

2 = 6322 or M1-low-shortage 　 2N* -3 6322 　 -3+ M1-list 3* -3+ 6(3)22

2NT = M1-middle-shortage 　 3* -3+ M1-list

3 = Equal-Residue 　 3* -3+ E1-list

3+ = M1-high-shortage 　 --> 　 M1-list

Note: In 7321 shapes the 2- and 3-card fragments are not identified.

Example:

	1	10-14, 4+ Spades (denies 4 Hearts).
1NT*	2	Single suited hand.
2*	2NT	Middle shortage.
3*	3	6-3-1-3.

Had I bid 2 instead of 2NT this would have shown a low shortage (Clubs) therefore a 6-3-3-1 hand. Had I missed 2 and 2NT out all together, then I would have shown a high shortage (Hearts). A 6-1-3-3 hand.