Discovering a 4-4 fit in a major suit can produce excellent contracts. Unfortunately, many players don’t know how to search for the match.

Here’s a North-South pair, with South dealing:

        NORTH
        ♠️ Q J 10 6
        ♥️ K 6 4
        ♦️J 6 5 4
        ♣️ J 2

        
        SOUTH
        ♠️A 7 5 4
        ♥️ Q J 10
        ♦️ 7 3 
        ♣️ A K10 3

The bidding proceeded as follows:

South            North
1♣️            1♦️
1NT            Pass

Where was the fault?

After North responded 1♦️, South figured that the logical rebid was 1NT. It’s not that a 1NT contract was awful, but that 2♠️ was more logical.

Some players think that to respond in a major, you need a five-card suit. Not so! Feel free to bid a four-bagger.

My editor Paul Laliberte makes another point. “Beginners would blame South for bypassing a four-card major. I believe the fault lies with North. With a hand worth only one bid unless forced, North should bypass a poor diamond suit and respond 1♠️.

Bidding 1♦️ serves no real purpose.” 

Now let’s try another auction. Again, South is dealing:

        NORTH
        ♠️ A Q 5 4
        ♥️ A 10 9 4
        ♦️ K Q 4 3
        ♣️ 3

        
        SOUTH
        ♠️ K 3 2
        ♥️ K Q J 2
        ♦️ 6
        ♣️ A J 5 4 2

The bidding proceeded as follows:

    South            North
    1♣️            1♦️
    1♥️            4NT            
    5♠️*            6♥️
    Pass

*Shows two of the five key cards (four aces, trump king) and the trump queen
Holding an opening hand with more than one bid, North can afford to respond 1♦️. 

Without the heart fit, North-South might have been stuck in a much less satisfactory NoTrump contract. With 4-4, bid more.