FROM “SAYC” TO “TWO OVER ONE”
more discussion from
SAYC vs 2/1

If you started to play bridge using Standard American (SAYC) here we explain some differences between SAYC and 2/1:
 
1- 1NT Forcing
Playing SAYC when you open in a major suit and Responder bids 1NT that shows 6-10 hcp then in the following hands:
a)
AQ A108xx K10xx xx you bid 2;
b)
AQ A108xxx K10x xx you bid 2;
c)
AQx A108xx K10x xx you bid pass.
So with 5332 distribution and 12-14 hcp in SAYC you should pass in the response of 1NT and the bidding may stop in 1NT. But in case Responder has a long minor suit, and has no sure entries in his hand, he may be prevented in make more than 1 trick in his long suit with a good defense like in this example:
Opener:
A10x AQ108x K10x xx
Responder:
8xx xx Jx KQJ10xx
Opener Responder
   1
      1NT <= SAYC 6-9 hcp
  pass

Of course, some SAYC partnership to avoid this loser situation make agreement that the response of 2
(or 2) followed by the rebid of 3 (or 3) is a rule to stop the bidding. 
But if Opener has 18-19 hcp and bids 3NT having 2 low cards in partner’s minor suit we have a problem in play 3NT because the information of 3
♣ (or 3) rebid was bypassed. 
Opener:
AKx AJ742 AQx xx
Responder:
8xx 6x xxx KQJ109x
Opener Responder
  1
        2 <= 10+ hcp
 3NT      pass?!
Thus, this adapted convention doesn’t allow reliable information.

A Bidding System must ensure the range of the strength of some bids. The response of 1NT forcing after a major opening is an evolution to solve this problem.
----------------------------------

Playing 2/1 after a major suit opening the response in 1NT is forcing one-round and has also a wider range of 5-11 hcp.
In case Opener has 5332 and 12-14 hcp, after Responder bid 1NT, Opener must bid his cheapest minor at level 2 with 3 cards:
Opener:
AQx A108xx K10x 10x
Responder:
8x 7x xx KQJ9xxx
Opener Responder
  1
        1NT <= 2/1 5-11 hcp
  2
          3  <= sign-off
pass
Now Responder sign-off the bidding making his long suit being trump’s suit.
------------------------------------


Another advantage of 1NT forcing is that playing in 2/1 we may distinguish an invitation support (10-11 hcp) of 3 cards from an invitation support of 4 cards.
Opener Responder
   1
       3  <= limit bid 4 cards support 10-11 hcp
Opener Responder
   1
      1NT  <= forcing
 2minor 3
  <= limit bid 3 cards support 10-11 hcp

Note: the information of support of 3 cards or 4 cards when the trump suit has only 1 top honor is fundamental to decide between stop the bidding or try a game even with 14 hcp.
-------------------------------------

2- Inverted Minors
This convention came from KS Bidding System in the 50s to allow Game Force (GF) support in a minor opening. In the early SAYC the support 1
- 2 or 1 - 2 was made with 6-9 hcp and the support 1 - 3 or 1 - 3 was made with 10-11 hcp. So, in the beginning of SAYC does not exist a directly minor agreement bid to show 12+ hcp!

This problem was resolved initially using “Criss Cross convention” to distinguish a hand of 12+ hcp from an invitation or weak hand using the artificial bid of 2 and 3 after 1
opening or the artificial bid of 3 after 1 opening. Thus, playing Criss Cross we have:
Opener Responder
  1
        2 <= 12+ hcp - game forcing
  1
        3 <= 5-9 hcp – preemptive bid
  1
        2 <= 10-11 hcp – invitation bid
  1
        2 <= 12+ hcp – game forcing
  1        3 <= 5-9 hcp – preemptive bid
  1
        3 <= 10-11 hcp – invitation bid
But using Criss Cross we lose the weak (or strong) bid response in the other minor to made possible the use of this Cris Cross convention.


Now on 2/1 system it is standard the follow convention of Inverted Minors that use support
at level 2 showing 10+ hcp and the support at level 3 showing 5-9 hcp. Of course, this gives partnership more space at level 2 to explain cooperatively their hands.
Opener Responder
1
        2 <= 10+ hcp 4+ cards – one-round force
1
        3 <= 5-9 hcp 5+ cards – Opener may pass
1
        2 <= 10+ hcp 4+ cards – one-round force
1
        3 <= 5-9 hcp 5+ cards  – Opener may pass

With this convention after Opener rebid his minor or bid 2NT, both bids showing 12-13 hcp, allow Responder to pass with 10-11 hcp. After Opener rebid 2NT Responder rebidding his minor shows 10-11 hcp, of course a sign-off, then Opener must pass.
Thus, Inverted Minors do not loses a bid in other minor!
Opener Responder
 1
       2 <= 10+ hcp with 4+ one-round force
 3
 <= 12-13 hcp Responder pass with 10-11 hcp

 1
       2 <= 10+ hcp with 4+ one-round force
 3
<= 12-13 hcp Responder pass with 10-11 hcp

 1
       2 <= 10+ hcp with 4+ one-round force
2NT <= 12-13 hcp Responder pass with 10-11 hcp

 1
       2 <= 10+ hcp with 4+ one-round force
2NT <= 12-13 hcp Respond
er pass with 10-11 hcp

Read more about Inverted Minors in Part 5
-------------------------------------

3- Splinter in 4
response after 1 opening
Playing SAYC after a major opening the splinter (convention to show shortness in the suit bid at level that guarantees 4+ cards support and 10+ hcp) was initially made only in minors suit
Opener Responder
   1
      4 <= splinter with 4♠+ cards support
                           
J10xx Axx x KQ10xx
Opener Responder
   1
      4 <= splinter with 4♠+ cards support
                          
Axxx K109 KJxxx x
because the 4
response was to play in Hearts
Opener Responder
   1
       4 <= to play
 
8x KQJ987xx x Jx or
 
Jx KQ109876 KJ9 x   
 
Playing 2/1 we may splinter in 4
because biding first 1NT forcing then 4 it is to play
Opener Responder
   1
      1NT <= forcing – waiting Opener’s second bid
2minor  4
  <= to play Jx AQJ109xx x Qxx
So, NT forcing permits response in 4
to be use as splinter
Opener Responder – playing 2/1
   1
      4/4/4 are splinter with 4+ cards support
-------------------------------------

4- Responder after bid 1NT (5-11 hcp) may rebid 2NT to show 10-11 hcp

After a major opening it is standard for SAYC or 2/1 the use of response in 2NT (Jacoby Game Force - GF) to show support 4 cards with 12-16 hcp without singleton. But when Responder’s hand has 10-11 hcp without support SAYC and 2/1 have different approaches:

For SAYC it is allowed to Responder bid a 5+ cards suit at level 2 with 10-11 hcp and then pass if Opener bids 2NT showing 12-13 hcp in a 5332 distribution.
For 2/1 Responder need 12+ hcp to bid a suit at level 2 (because that it is GF), so hands with 10-11 hcp without support Responder must first bid in 1NT. Then, with 10-11 hcp Responder may bid 2NT.

So, playing 2/1 after a major opening Responder with 5-11 hcp has how to inform in his second bid if his range is 5-9 hcp or 10-11 hcp:

A- without  3+ cards support with 6-9 hcp balanced hand then bid 1NT.
Opener Responder
   1
      1NT
   2
        ?
a)
Jx A109x Jxxx Qxx => 2
    
sign-off - just preference
b)
Jx 109x KJ10xxx Qx => 2
     
sign-off – only play in his long suit
c) xx J9x K9xx QJ10x => pass
     Opener may have 3
+ cards
d)
Kx J9x J9xx QJ10x => 2
     support with honor second


B- without 3+ cards support with 10-11 hcp Responder must bid first 1NT
Opener Responder
   1
      1NT
   2
        ?
d)
Jx AJ10x KJ10x J9x => 2NT
    invitation to 3NT with 10-11 hcp
e)
Jx K9x KJx K109xx => 3
    shows 5
+ cards support and 10-11 hcp
f) xx AQ987x KJx 10x => 3
    shows 6
+ invitation for 4 with 10-11 hcp
g) Qxx AQ98 Kxxx 10x => 3
    shows 3
cards support with 10-11 hcp
--------------------------------------

5- After a major opening and a minor response SAYC and 2/1 have differences concepts. SAYC loses space (for cuebids) when jumping to show a game-force hand (GF). Playing 2/1 we use the Fast Arrive Principle where jumping to game shows a minimum opening hand after Responder bids a GF. In other hand, 2/1 uses Slow Arrive to keep space to cuebid when have a strong opening hand.

Playing 2/1
Opener Responder
  1
♠        2♣ / 2 / 2 are GF with 12+ hcp
Opener Responder
  1
      2 / 2 are GF with 12+ hcp
Opener Responder
  1
      2 is GF with 12+ hcp

But playing SAYC all of these possible bids shows 10+ hcp and forces the bidding until 2NT or at level 3 of the Opener suit or the Responder suit. But need jump to be GF.
Thus, playing 2/1 after a response bid at level 2 in other suit up the line this starts a GF sequence and it is more easy to exchange information about distribution/suit and strength of their hand because the bidding will not stop at 2NT and nor at level 3 in Responder suit.

The lemma for 2/1 in this sequence is: IN GF SEQUENCE
LOWER YOU BID MORE STRONG YOU ARE. This is known as the Principle of Fast/Slow Arrive because with a minimum hand 12-15 hcp you must go to the game as soon as possible and with a hand 16+ hcp you must show your honor before bid game.
But in SAYC the lemma is: STRONGER YOU ARE HIGHER YOU BID, and this demands a jump in Opener’s suit or in Responder’s suit. The jump cut space for more clarification of hand.

Playing SAYC with 12-13 hcp Opener just invite
Opener Responder
  1
        2
  3
<= AJ765 J9x KJx Kx <= 12-13 hcp
             If Responder are 10-11 hcp may pass

Playing SAYC with 14-16 hcp Opener jumps to game
Opener Responder
  1
        2
  4
<= AJ765 Q9x KJx Ax  <= 14-16 hcp

Playing 2/1 we use the Fast Arrive after GF
Opener Responder
  1
        2
  4
<= Fast Arrive: AJ765 J9x KJx Kx 12-15 hcp
Opener Responder
  1
        2
  3
<= AK765 Q9xx KJx Ax <= 16+ hcp
The basic idea it is keep space for cuebid (A or K)

6- In the early years of bridge contract, after 1NT opening 16-18 hcp, players understand the importance of the contract being played in the long suit of Responder’s hand. Then, when Responder was 5-card major in distribution 5332 and less than 7 hcp a 5-card bid at level 2 was a pure sign-off.
Opener Responder
  1NT     2
/2 <= sign-off
  pass
Responder’s hands possible:
K7652 9xx Jxx xx <= 2
1087652 9xx AJx x <= 2 
52 QJxxx QJxx xx <= 2
KJ5 9J107543 Jxx x <= 2 

Then experts play start to understand that if the strong hand receive the lead the chances of success increase and players like Oswald Jacoby (1902-1984) start to use the transfer for majors after 1NT or 2NT opening.
Opener Responder
  1NT     2
   <= transfer to 2
   2       ?
            pass less than 7 hcp
             3
<= invitation 7-8 hcp
             4
<= to play 9+ hcp
 pass
Opener Responder
  1NT     2
   <= transfer to 2
  2 <= pass less than 7 hcp
             3
<= invitation 7-8 hcp
             4
<= t0 play 9+ hcp
 pass

In fact, after 1NT opening the response in 2
was an artificial bid asking for major suit, but then in SAYC Bidding System the 1NT responses was improve with 2 being a Stayman for minors or being a transfer for minors with 6 cards minors with less than 7 hcp. So, the responses at level 2 was:
Responder Opener
                   1NT
   ?
  2
<= Stayman for majors
  2
<= transfer to 2
  2
<= transfer to 2
  2 <= Stayman for minors
2NT<= invitation
   or
Responder Opener
                   1NT
   ?
  2
<= Stayman asking for majors
  2
<= transfer to 2
  2
<= transfer to 2
  2 <= transfer to 3
                   3
<= pass or correct
  So, Responder pass with 6
cards
  or bid 3
pure sign-off
2NT<= invitation
The SAYC Bidding System uses the bid of 3
or 3 not as pure sign-off but as an invitation bid with 7/8 hcp and a top honor with 6 cards.
Opener Responder
  1NT     3
   <= invitation to 3NT
  pass <= only Hx or xxx or 15 hcp
  3NT  <= 16+ hcp and Hxx
where Hx = Top Honor (A/K) 2 cards
where Hxx = Top Honor (A/K) 3 cards
Opener Responder
  1NT     3
   <= invitation to 3NT
  pass <= only Hx or xxx or minimum
  3NT  <= 16+ hcp and Hxx  

Responder’s hands possible:
10x Jxx xx xAJ10xxx <= 3
5x Qxx Jx KJ9843 <= 3 
Qx 10xx AJ10xxx xx <= 3
Q95 943 KQ109xx x <= 3 

How these transfers and invitation works in 2/1?

First all in 2/1 advance partnerships reserve any response bid after 1NT opening to show 2 minors suits 5-4 or 5-5. Second, they don’t use response in 2NT as invitation to 3NT but as a specific transfer bid to 3 and use the 2 bids as a specific transfer to 3. Both transfers to minors use a pre-accept information from 1NT Opener saying good hand with Hxx support or bad hand without Hxx support.

Opener Responder
 1NT      2
<= transfer to 3
   ?
 
3 <= I like this suit because I have 16+
             hcp and
Hxx (Axx or Kxx)
 2NT <= I don’t like

Opener Responder
 1NT       2NT <= transfer to 3
 
   ?
  3
<= I like this suit because I have 16+
             hcp and
Hxx (Axx or Kxx)
  3
<= I don’t like
 
So, playing 2/1 to make invitation with 8/9 hcp Responder bids 2
and after bids 2NT.

In this 2/1 propose we use after 1NT a response in level 3 to show a GF hand with both minors in distribution 5431 or 5521 and strength 10-14 hcp:
Responder Opener
……………..  1NT
  ?
 3
<= 3-1-5-4 or 3-1-4-5
 3
<= 3-1-5-4 or 3-1-4-5
 3
<= 2-1-5-5 
 3
<= 1-2-5-5       
-------------------------------

Bottom Line:
Comparing SAYC and 2/1 we observe that the information about strength of Opener and Responder hands, in 2/1 are easier and clearer, and this allow partnership to have more space to interchange information about suits control (Ace/King/singleton/void) when slam is possible.