bidding "up the line"

[11WAMMER]

No bidding by the opposition. I opened the bidding 1♦, partner has 4-1-4-4 distribution with a singleton ♦ and 13 hcp. His response was 2♣. I claim that his bid denies a 4 card major. He claims that he is bidding "up the line" and does not deny a 4 card major. My position is that "up the line" starts with the next available bid, in this case 1♥. His position is that "up the line" starts at clubs at the next available level. Please help us resolve this dispute.

[Stephen Tu]

• It's normal to write "4=4=1=4" order to say partner had a singleton diamond, order SHDC, easier for people to read.
  
• 1♦-2♣ *does not* deny a four card major in SA bidding. However, if a four card major is held, it implies longer clubs (5+) and a game forcing hand. So your partner is wrong to bid 2♣ with only 4 clubs and this shape, but you are also wrong in assuming it denies a 4 card major. Natural systems like SA are based on bidding the longest suit first, so bidding clubs first does not deny a major, just shows the clubs are longer. But bidding clubs then a major forces the bidding to too high a level when holding less than a game force, so with a weaker hand you bid the major first even with longer clubs, in order to find the high scoring major partials. There exist systems where 1♦-2♣ denies a major, but SA/SAYC is not one of them. These other systems also require some gadgetry in order to be able to show a good hand with longer clubs later, if you have to show the major first.
   
  
• "up-the-line" means bidding the cheapest of 4 cd suits when only 4 cd suits are held. Not clubs first. But up-the-line doesn't apply when having longer clubs and a GF hand (2♣ is correct with GF, 3=4=1=5 shape, for example).
   
  
• for tactical reasons, people may occasionally, perhaps even frequently, skip over a 4cd ♦ suit to bid a 4cd major, when partner opens 1♣. Some even skip over longer diamond suits holding weak hands to bid a major, but this isn't strictly "SAYC" by the notes, it's a "Walsh" influence.
  

[11WAMMER]

Thanks Stephen for a very clear reply. Much appreciated.

[ArtK78]

I am curious. What did your partner think that "up-the-line" meant?

[655321]

I am curious.  What did your partner think that "up-the-line" meant?

His position is that "up the line" starts at clubs at the next available level.