Blackwood may be the most popular convention in bridge. In search of a possible slam, players bid 4NT. The answers:

• 5♣: zero or four aces.

• 5♦: one ace

• 5♥: two aces

• 5♠: three aces

With all four aces and interest in a grand slam, players now bid 5NT for kings, with the same answers.

There’s also a more ambitious form of Blackwood called Roman Key Card Blackwood, in which the answers to 4NT typically are:

• 5♣: zero or three of the five “key cards” (four aces, trump king)

• 5♦: one or four

• 5♥: two or five without the trump queen

• 5♠: two or five with the trump queen

Bidding 5NT now may ask for total kings or the lowest one, depending on systems.

The problem is that many players assume Blackwood is the only route to slam. Actually, there are times to use it, and times you most assuredly don’t.

When to use Blackwood of any kind:

Bid 4NT when you have slam prospects and no suit with two quick losers:

♠A K J 4 3

♥K Q 10

♦10

♣A Q 6 4

You, partner

1♠ 3 ♠

4NT

• Limit raise showing 4+ spades and 10-12 support points

If partner shows one ace, you can safely bid 6♠.

When not to use Blackwood:

1) When it’s more appropriate to bid “controls.” A control is a bid in a suit that has no more than one quick loser. You should bid controls rather than Blackwood when you have a suit with a worthless doubleton or more.

♠A K J 4 3

♥K Q J

♦10 4

♣ A 10 6

You, partner
1♠ , 3 ♠

?

Bid 4♣ to show a control in that suit. If you instead bid Blackwood and partner shows one ace, you won’t know if it’s in hearts or diamonds. You might have two quick diamond losers.

Naturally, after you show your club control, you hope partner will bid 4♦ to show a control in the suit you’re worried about. If partner skips over diamonds, you can safely settle for 4 ♠.

2) When partner bids 1NT and you have a similar hand with at least 16 points.

You hold:

♠A Q 4

♥K J 10 2

♦A J 10

♣J 10 9

1NT Pass ?

Bid 4NT. This is not Blackwood. It’s a “quantitative” bid asking partner to bid 6NT with a good 16-point hand or a 17-pointer. With neither, partner should pass.

Suppose you think a NoTrump slam depends on aces rather than total points. Playing Bridge Base Online, my partner opened 1NT, showing 15-17 high-card points. I held:

♠K J 9 5 4

♥J 7 3

♦A 7

♣A K J

With my strong 17-pointer, I felt certain that we’d make 6NT unless we were missing two aces. So I bid 4♣, the Gerber convention. Answers:

• 4♦: zero or four aces

• 4♥: one ace

• 4♠: two aces

• 4NT: three aces

(Advancing to 5NT would ask for kings in search of a grand slam. We didn’t have the points for that inquiry here.) When partner responded 4♠, showing both missing aces, I bid 6NT, making.

Got all that?