| Vulnerability: Neither | 
| N | E | S | W | 
| ♠  5 3
♥  A K
♦  T 8 7 6 5 3 2
♣  4 3
 | ♠  K 7 6 4
♥  Q J 9 2
♦  Q 9 4
♣  T 8
 | ♠  Q T 9 8 2
♥  5 3
♦  A K J
♣  K J 2
 | ♠  A J
♥  T 8 7 6 4
♦  
♣  A Q 9 7 6 5
 | 
| Dealer: North   (Both Pairs bidding Simplex) | 
| 2♦  (1) | Pass  (2) | 2NT (3) | Dbl  (4) | 
| 3♦  (5) | 3♥ (6) | Pass  (7) | 4♥  (8) | 
| end |  |  |  | 
| Notes when South is Dealer:  P2, P15: 6-card suit but 7 HCP, so not strong enough to bid at the 1-level.  Note that the diamonds are bid despite the lack of honours in the suit.
 P8: Only 8 HCP and no 5+ card suit.
 P16:  3-card diamond support and 14 HCP.
 P17: West's 11 HCP hand could have been opened both 1♣ and 2♣.  But the bids of both North and South have taken those bids away, so normally West should not double.  However, West is two-suited, and had North opened 1♦ — typically a stronger bid than 2♣ because of the higher HCP range — West could also have overcalled 1♥.  So double is appropriate here.
 North makes a minimum rebid with 3-9 HCP. 
 East bids his cheapest 3+ card suit in response to the double.  His 8 HCP is sufficient.
 South has bid the full extent of his hand already.
 With East now showing 4+ card support for hearts, West can revalue his hand to 16 points, allowing 5 shortage points for his void.
 | 
| Dealer: South  (1)  (Both Pairs bidding Simplex) | 
| N | E | S | W | 
| - | - | 1♠  (2) | 2♣  (3) | 
| 2♦  (4) | Pass (5) | 2NT  (6) | 3♥  (7) | 
| Pass (8) | 4♥ (9) | end |  | 
| Notes when South is Dealer:  P14: As a test of Simplex's dealer-independence, we examine the bidding when the dealer is South instead of North.
 P1: 14 HCP and a 5-card suit.
 P2:  6-card suit and 11 HCP.
 P2:  6+ card suit and 7 HCP.
 With only two clubs and less than 13 HCP.
 P16: 3-card diamond support and 14 HCP.
 P21: West has a hand good enough to open at the 1-level, and another 5-card suit he can bid at the 3-level, even though his partner passed.
 As West has overcalled, North can pass South's 2NT enquiry to show his low point-count.
 East has 4-card support for West's five hearts, and is worth about 9 points.  East knows West has at least 8 HCP and at least 11 cards in hearts and clubs, which implies he has at least 6 shortage points.  That makes a minimum total of 23 points between them.  But West could have 8 more HCP — the range for a 1-level bid is 8-16 HCP — so a game bid is a good bet.
 | 
| Dealer: West  (1)  (Both Pairs bidding Simplex) | 
| N | E | S | W | 
| - | - | - | 1♣  (2) | 
| 2♦  (3) | Dbl (4) | 2NT  (5) | 3♥ (6) | 
| 4♦ (7) | 4♥ (8) | end |  | 
| Notes when West is Dealer:  P14: As a test of Simplex's dealer-independence, we examine the bidding when the dealer is South instead of North.
 P0, P1, P2, P3: 11 HCP and a 5+ card suit.
 P2:  A 6+ card suit with not enough HCP to overcall at the 1-level.
 P2:  With 8 HCP and only 2-card support for West, East could have bid 1NT, but North's bid has prevented that.
 P13, P16: 3-card diamond support and 14 HCP.
 In response to East's 'negative double', West introduces his unbid 4+ card suit.
 As West has overcalled, North can pass South's 2NT enquiry to show his low point-count.  But he has seven cards in diamonds, and therefore bids to the Total Trump level of 4♦, given South's minimum holding of 3 cards.
 East takes a gamble.
 |