Some slam deals from semifinals

Robot versus human slam bidding is compared, albeit with a very limited number of deals. The robot semifinals used 32 boards from the human team championships (Open, Women, Senior, Mixed) round of sixteen and 32 boards from the human quarter finals. There are only four deals that fit the criteria of slams that are 60% or better. Determining a 60% slam may depend on the opponents’ bidding as it might place cards in a favorable position that increases the probability of success (1).

Human quarter-finals: [A (1)] Board 4 (6); [B] board 14 [7♠]; and [C] board 20 (6 best).
Human Round of 16: [D] Board 18 (6♦, 90% or 7♦, 60%)

[A (1]]

Board 4
Dlr: W
Vul: None
.
.
North
♠ 532
AQJ4
Q3
♣ A653
West
♠ AQ6
K8732
T
♣ QJ84
East
♠ JT984
T5
J74
♣ KT7
South
♠ K7
96
AK98652
♣ 92
West
Shark Bridge
1♥
2♠
Pass
Pass
.
North
Wbridge5
Pass
Dbl1
4NT
6
.
East
Shark Bridge
1♠
Pass
Pass
All Pass
.
South
Wbridge5
2
3♥2
53
.
.

Opening lead ♣Q
1 some strength with 4+ clubs
2 spade stopper, looking for heart stopper for NT
3 1 ace

While it looks like a bad slam looking at N-S cards, the opponents’ bidding makes it a reasonable slam for an expert declarer. With West marked for the heart king and length, and most likely the space ace, the slam depends on picking up the trump suit with two leads toward the South. The play proceeded: club ace; diamond queen overtaken with the ace; heart finesse, diamond finesse (restricted choice); running diamonds and on the last diamond West had no safe discard.

.
.
North
♠ 53
AQ4

♣ —
West
♠ AQ
K87

♣ —
East
♠ JT
T

♣ KT
South
♠ K7
9
2
♣ 9

At the table West discarded the ♠Q, declarer led a spade to West’s stiff ace and West had to return a heart, +1370. At the other table, Shark Bridge played in 3, +130.

In the Micro Bridge versus Bridge Baron match, at one table Bridge Baron was in 4  +130. At the other table.

West
Bridge Baron
1
Dbl1
Pass
.
North
Micro Bridge
Pass
Pass
5
.
East
Bridge Baron
1♠
3♠
All Pass
.
South
Micro Bridge
3
Pass
.
.

Opening lead 3
1 Three spades

The opening lead of a low heart, finessed, and on the run of diamonds West was similarly squeezed, +620. Note that the play must be the same to make both 5 and 6. At the other table, Bridge Baron played in 4♦, +130.

In robot play the four contacts were 3 (Shark Bridge), making 4, 4♦, making 4 (Bridge Baron), 5, making 6 (Micro Bridge) and 6, making 6 (Wbridge5).
Of the 32 times the deal was played by ‘humans’ the contracts were: 3NT by South (17); 3NT by North, down (2); 3 (7); 3♠ by East (2); 5, down (2), making with an overtrick (1); and 6 making (1).  The human declarers that made 5 and 6received the spade ace lead, so were not tested in the play.

[B]

Board 14
Dlr: E
Vul: None
.
.
North
♠ QT
965
QJ532
♣ 652
West
♠ 9652
K
A94
♣ AKJ74
East
♠ AKJ853
A84
K6
♣ T9
South
♠ 7
QJT732
T87
♣ Q83

Robot play: 7♠ (2, Wbridge5 and Bridge Baron) and 6♠ (2, Micro Bridge and Shark Bridge). In human play: Open, 7♠ (7) 6♠ (1); Women, 7♠ (5), 6♠ (1), 6NT (1), game (1); Senior 7♠ (3), 6♠ (5); Mixed, 7♠ (6), 6♠ (2).

[C]

Board 20
Dlr: W
Vul: Both
.
.
North
♠ J64
J862
832
♣ K95
West
♠ AK2
KT54
T7
♣ AJ32
East
♠ 875
A73
AKQ94
♣ QT
South
♠ QT93
Q9
J65
♣ 8764

6 is quite a reasonable contract, as it makes if theJ falls doubleton or tripleton, or if the club finesse works and hearts are 3-3.  No human or robot was in slam.

[D]

Board 18
Dlr: E
Vul: N-S
.
.
North
♠ A3
QT
KJ98432
♣ K3
West
♠ J742
K98
T76
♣ 752
East
♠ QT95
76543
Q
♣ Q86
South
♠ K86
AJ2
A5
♣ AJT94

Robot play: 7 (1, Micro Bridge), 6NT (1, Wbridge5), 3NT (2, Shark Bridge and Bridge Baron).
Human play: Open, 7 (3), 6 (7), 6NT (2), game (3) 7NT (bad grand) (1); Women, 6 (13), game (3); Senior, 6NT (4), 6 (10), game (2); Mixed, 7 (1) 6 (9), 6NT (2), game (4).

For a good defensive play, exchange a few cards, East opens 2, and the contract is 7 N, opening lead ♠ T.

Board 18
Dlr: E
Vul: N-S
.
.
North
♠ A3
QT
KJ98432
♣ K3
West
♠ J754
762
QT76
♣ 752
East
♠ QT9
K98543

♣ Q86
South
♠ K862
AJ
A5
♣ AJT94

Now exchange a few cards, and East opens 2H.
7 N, opening lead ♠ T

Spade ace; diamond to ace; diamond to 9; club king; club ace; club ruff; spade king; spade ruff; heart T (does East put up the king!) or heart queen (does East duck!), if not, win in hand; club ruff; heart to ace; club!.

Looking at the two finalists:

[A] Robot play: 5, making 6 (Micro Bridge); 6, making 6 (Wbridge5), 3/4, +130 (Shark Bridge/Bridge Baron)
Humans got to excellent 3NT-S (17/32), and good 5 (3), -50 twice and +420 once, and 6 (1) making. A number of poor results, 3, +130 (7), 3NT from wrong side, down (2) and 3♠ by opponents, +50 (2).
(likely/actually)
Micro Bridge: +2/3
Wbridge5: +9/12
Bridge Baron -4/-6
Shark Bridge -4/-6

[B] Robot play: 7♠ (2, Wbridge5 and Bridge Baron) and 6♠ (2, Micro Bridge and Shark Bridge). In human play: Open, 7♠ (7) 6♠ (1); Women, 7♠ (5), 6♠ (1), 6NT (1), game (1); Senior 7♠ (3), 6♠ (5); Mixed, 7♠ (6), 6♠ (2).
Micro Bridge: -4
Wbridge5: +4
Bridge Baron +4
Shark Bridge -4

[C] perfect result: +0 for all

[D] Robot play: 7 (1, Micro Bridge), 6NT (1, Wbridge5), 3NT (2, Shark Bridge and Bridge Baron). Human play: Open, 7 (3), 6 (7), 6NT (2), game (3) 7NT (bad grand) (1); Women, 6 (13), game (3); Senior, 6NT (4), 6 (10), game (2); Mixed, 7 (1) 6 (9), 6NT (2), game (4).
7 is 60%; 6 is 90%, 6NT is 80%. All three contracts are even in expected Imps, for +2 for both Wbridge5 and Micro Bridge.
(likely/actually)
Micro Bridge: +2/+10
Wbridge5: +2/+1
Bridge Baron -7
Shark Bridge -7

Overall (likely/actually)
Micro Bridge:0 /+9
Wbridge5: +15/+17
Bridge Baron -7/-9
Shark Bridge -15/-17

In their bot-to-bot semifinal matches, Wbridge5 was +39 Imps against Shark Bridge and Micro Bridge was +15 Imps against Bridge Baron.

While quite approximate given the limited sample and cursory analysis, it does show that the two top robots, on these slam deals, would have held their own in this world championship field.