Raising opener's rebid suit to the three-level (as in 1
♠-2
♦-2
♠-3
♠) should be forcing. Again, the inference is that the 2
♠ rebid did not guarantee a sixth spade (it would be normal to rebid 2
♠ there with a balanced minimum, or a minimum with spades and clubs). So how many spades does responder have? With only two it is odd to raise a five card suit to the three-level... and with three and an invite, he would've bid 1
♠-3
♠ directly. This is not a "preference" auction like 1
♠-2
♦-2
♥-2
♠ where it is normal to "pick one of partner's suits." So the three-level raise should be three spade and forcing.
To support responder's suit with 13-14 points, start by rebidding your major. Partner will now do something (remember the major suit rebid is forcing). This will normally give you the chance to raise at the next turn. For example:
1
♠ - 2
♣ - 3
♣ Club raise with extras, forcing because responder promised a rebid.
1
♠ - 2
♣ - 2
♠ - 2NT - 3
♣ Club raise with a minimum; now we can get out in three clubs.
The exact range of 1
♠-2
♣-2NT depends on your opening tendencies. Some people will always open 1NT with 5
♠-332 and 15-17 points, some will always open 1
♠, some will do a bit of each depending on the hand. SAYC doesn't really have a policy on this. In any case the 2NT bid is forcing (responder promised a rebid remember) and therefore shows enough for game opposite 10.
Rebidding the first suit does not actually limit the hand. The typical example is something like
♠Q87542
♥AK9
♦AK2
♣5. You open 1
♠ and partner bids 2
♣. Do you
really want to bid 3
♠ on this terrible suit? It will take up all your bidding room, and partner will assume you have good spades. He will often be weak in one (or both) of the red suits given your holding, and may decide to bid 4
♠ on a singleton rather than 3NT with a red suit (from his hand) wide open. In all it is much better if your jump-rebid shows a good suit, meaning you may have to rebid 2
♠ on hands like these. There are other examples too. But that being said, the 2M rebid is
usually just 13-14 points and partner will normally take you for that.
There isn't usually a reason to jump around in these 2/1 auctions. Most good players will play a jump to the four-level (i.e. 1
♠-2
♥-4
♣) as a splinter, but this is not part of the basic SAYC card (it is a "recommended" add-on though). Without an agreement to play splinters I suppose this auction is a very strong two-suiter, but I'm sure that I've never had occasion to bid it that way.
The above agreements are based on the SAYC lessons taught on OKB for many years, and are mostly a logical consequence of what's written in the SAYC system booklet. Most of it is inference -- for example, we know that 1
♠-3
♠ is limit raise and shows 3+ spades. So logically other sequences like 1
♠-2
♣-2
♥-3
♠ should not be a limit raise with three spades. It does not actually
say anywhere that this is not also exactly the same hand as 1
♠-3
♠, but logically it shouldn't be. Similarly, it doesn't
say anywhere that 1
♠-2
♣-2NT shows extras, but it does say that responder could have a balanced 10 and responder must bid again (promises rebid) so logically it should show extras.
There are some who will argue that logic should not be applied to SAYC (or even to bridge in general) but I'm not among them.
As for what "most people play on BBO" I very much suspect it is more the nebulous "standard american" variety where basically nothing is forcing and you never know what you're going to get. Most of the expert crowd prefers to play 2/1 GF.
Adam W. Meyerson
a.k.a. Appeal Without Merit