BERKOWITZ David · WOLFSON
63rank
+9.9Butler · 80 bds
+0.12per board
±3.8swing
+0.44vs par /bd · #38/148
+0.20adjusted /bd
by round
vs par split: bidding +0.53 · play -0.09
Strength of schedule: opponents averaged +0.07/bd (a tough draw) → opponent-adjusted +0.20/bd
Card play — on target: opening leads 55.0% #146 of 148 · declarer play 65.2% #126 of 148 · defence 87.2% #60 of 148
| vs NT | vs a suit | |
|---|---|---|
| Opening leads | 83.3% (6) | 42.9% (14) |
| Declarer play | 62.5% (8) | 66.7% (15) |
| Defence | 75.0% (16) | 95.7% (23) |
Opening leads by suit led: ♠ 100.0% (2) · ♥ 60.0% (10) · ♦ 25.0% (4) · ♣ 50.0% (4)
vs par by strain: NT -0.42 (31) · a suit +0.98 (49)
vs par by level: part-score +0.54 (35) · game +0.65 (40) · slam -2.00 (5)
By role: declaring +0.51/bd (-1.42 vs par · 41) · defending -0.28/bd (+2.38 vs par · 39)
By vulnerability: vulnerable +0.57/bd (+0.56 vs par · 41) · not vulnerable -0.35/bd (+0.31 vs par · 39)
By round↑ top
| Round | Partner | Opponents | Room | Bds | Butler | Avg | vs par |
|---|---|---|---|---|---|---|---|
| Round 1 | B.Hamman | A.Schwartz – Y.Levit | Closed | 10 | +10.1 | +1.01 | +3.50 |
| Round 2 | B.Hamman | R.Lin – J.Tao | Closed | 10 | +9.2 | +0.92 | +2.30 |
| Round 3 | B.Hamman | V.Markowicz – K.Moszczynski | Closed | 10 | -8.6 | -0.86 | +1.00 |
| Round 5 | B.Hamman | D.Stack – J.Russell | Closed | 10 | -17.7 | -1.77 | -3.80 |
| Round 6 | B.Hamman | L.Lewis – P.Lewis | Closed | 10 | -5.5 | -0.55 | +1.30 |
| Round 8 | B.Hamman | N.Hanna – J.Rayner | Closed | 10 | +5.9 | +0.59 | +0.80 |
| Round 9 | B.Hamman | J.Robles – R.Garcia | Closed | 10 | +10.5 | +1.05 | -0.20 |
| Round 10 | B.Hamman | S.Garner – M.Lair | Open | 10 | +6.0 | +0.60 | -1.40 |
Every board — best Butler first↑ top
vs par = IMPs this pair scored above (+) or below (−) the board’s double-dummy par — what bidding and play (theirs and the opponents’) added or gave away against perfect play.
| Butler | Round | Opponents | Bd | Contract | Lead | Res | vs par |
|---|---|---|---|---|---|---|---|
| +8.7 | Round 2 | CHINA EVERTRUST | 16 | 4♠ | ♥Q | +3 | +14 |
| +7.9 | Round 10 | MILNER | 13 | 6♣ | ♥J | = | -13 |
| +7.8 | Round 6 | LEWIS | 3 | 6♥ | ♠3 | = | +0 |
| +7.5 | Round 1 | KAMINSKI | 2 | 2♠ | ♦9 | = | +12 |
| +6.1 | Round 1 | KAMINSKI | 5 | 4♥ | ♦6 | -2 | +7 |
| +5.9 | Round 8 | CANADA SENIORS | 25 | 4♥ | ♠4 | -1 | +10 |
| +5.8 | Round 2 | CHINA EVERTRUST | 14 | 4♠ | ♥3 | +2 | +11 |
| +5.4 | Round 9 | CHILE SENIORS | 10 | 4♠ | ♦4 | -1 | +12 |
| +5.2 | Round 8 | CANADA SENIORS | 30 | 3NT | ♣J | = | +0 |
| +4.7 | Round 9 | CHILE SENIORS | 6 | 4♥ | ♠3 | -1 | +5 |
| +4.4 | Round 6 | LEWIS | 6 | 2♠ | ♦A | = | +6 |
| +3.9 | Round 3 | MARKOWICZ | 3 | 3NT | ♦J | -1 | +12 |
| +3.2 | Round 1 | KAMINSKI | 10 | 3NT | ♣3 | -2 | +8 |
| +3.2 | Round 3 | MARKOWICZ | 4 | 4♥ | ♠10 | -1 | +6 |
| +3.0 | Round 1 | KAMINSKI | 3 | 4♠ | ♦7 | -1 | +5 |
| +2.8 | Round 6 | LEWIS | 2 | 4♥ | ♦K | = | -1 |
| +2.8 | Round 6 | LEWIS | 10 | 1NT | ♣2 | = | +2 |
| +2.5 | Round 3 | MARKOWICZ | 10 | 2NT | ♥2 | -1 | +0 |
| +2.5 | Round 10 | MILNER | 19 | 2NT | ♠7 | = | +1 |
| +2.3 | Round 8 | CANADA SENIORS | 29 | 3♣ | ♥J | = | +0 |
| +2.1 | Round 5 | USARUSSELL | 21 | 3NT | ♣3 | +1 | +1 |
| +2.1 | Round 10 | MILNER | 14 | 3NT | ♣6 | +1 | +0 |
| +1.9 | Round 5 | USARUSSELL | 30 | 2♦ | ♠A | = | +0 |
| +1.9 | Round 8 | CANADA SENIORS | 24 | 4♥ | ♦7 | +1 | +0 |
| +1.9 | Round 9 | CHILE SENIORS | 3 | 2♦ | ♣4 | -1 | +4 |
| +1.8 | Round 9 | CHILE SENIORS | 5 | 2♠ | ♥6 | = | +5 |
| +1.5 | Round 5 | USARUSSELL | 24 | 6NT | ♣A | = | +0 |
| +1.4 | Round 2 | CHINA EVERTRUST | 19 | 2♥ | ♥J | +2 | +6 |
| +1.4 | Round 8 | CANADA SENIORS | 26 | 2♥ | ♠4 | +1 | +0 |
| +1.3 | Round 10 | MILNER | 20 | 5♣ | ♠A | = | -2 |
| +1.2 | Round 3 | MARKOWICZ | 9 | 3♠ | ♦A | +1 | +1 |
| +1.0 | Round 9 | CHILE SENIORS | 7 | 3♣ | ♦K | +1 | -11 |
| +1.0 | Round 10 | MILNER | 15 | 3NT | ♥10 | -2 | +7 |
| +0.8 | Round 2 | CHINA EVERTRUST | 12 | 2♦ | ♠Q | -2 | +1 |
| +0.8 | Round 9 | CHILE SENIORS | 8 | 4♠ | ♠2 | = | +0 |
| +0.5 | Round 6 | LEWIS | 9 | 3♠ | ♠4 | -2 | +5 |
| +0.4 | Round 8 | CANADA SENIORS | 23 | 3NT | ♠2 | +1 | +0 |
| +0.0 | Round 2 | CHINA EVERTRUST | 15 | 4♥ | ♦3 | = | +0 |
| +0.0 | Round 3 | MARKOWICZ | 6 | 3NT | ♠4 | = | +0 |
| -0.0 | Round 9 | CHILE SENIORS | 4 | 4♥ | ♣K | +1 | +0 |
| -0.1 | Round 1 | KAMINSKI | 7 | 3♣ | ♥3 | +1 | +0 |
| -0.1 | Round 6 | LEWIS | 7 | 4♥ | ♦J | +1 | +0 |
| -0.1 | Round 8 | CANADA SENIORS | 28 | 1NT | ♥Q | = | -1 |
| -0.2 | Round 10 | MILNER | 12 | 2♠ | ♥J | = | -1 |
| -0.2 | Round 10 | MILNER | 17 | 2♥ | ♣Q | = | +1 |
| -0.3 | Round 2 | CHINA EVERTRUST | 18 | 3NT | ♥4 | +1 | -1 |
| -0.3 | Round 5 | USARUSSELL | 25 | 3NT | ♥6 | +2 | +0 |
| -0.4 | Round 9 | CHILE SENIORS | 9 | 4♠ | ♥4 | +1 | -1 |
| -0.5 | Round 3 | MARKOWICZ | 5 | 5♣ | ♥4 | = | -2 |
| -0.6 | Round 8 | CANADA SENIORS | 21 | 3NT | ♠6 | = | +0 |
| -0.9 | Round 3 | MARKOWICZ | 2 | 1NT | ♥6 | +2 | +6 |
| -1.2 | Round 1 | KAMINSKI | 4 | 3♦ | ♥K | +1 | +10 |
| -1.2 | Round 6 | LEWIS | 4 | 4♥ | ♣K | = | -3 |
| -1.4 | Round 2 | CHINA EVERTRUST | 17 | 2♥ | ♥3 | = | +0 |
| -1.4 | Round 10 | MILNER | 18 | 1NT | ♦4 | -2 | +0 |
| -1.5 | Round 2 | CHINA EVERTRUST | 20 | 2♠ | ♦A | = | -1 |
| -1.6 | Round 1 | KAMINSKI | 1 | 3NT | ♦J | -2 | -5 |
| -1.6 | Round 1 | KAMINSKI | 6 | 3♠ | ♣K | = | -1 |
| -1.7 | Round 5 | USARUSSELL | 28 | 3♣ | ♠A | -2 | +0 |
| -1.9 | Round 2 | CHINA EVERTRUST | 13 | 6♠ | ♥J | +1 | -8 |
| -2.3 | Round 9 | CHILE SENIORS | 1 | 3NT | ♦9 | -1 | -10 |
| -2.4 | Round 2 | CHINA EVERTRUST | 11 | 1NT | ♥3 | = | +1 |
| -2.4 | Round 9 | CHILE SENIORS | 2 | 4♠ | ♦Q | -2 | -6 |
| -2.5 | Round 5 | USARUSSELL | 22 | 2♥ | ♠Q | +4 | -9 |
| -2.6 | Round 1 | KAMINSKI | 8 | 1NT | ♥Q | +1 | -1 |
| -2.6 | Round 1 | KAMINSKI | 9 | 2♣ | ♠Q | -1 | +0 |
| -2.7 | Round 6 | LEWIS | 5 | 1NT | ♠Q | +2 | +1 |
| -3.1 | Round 5 | USARUSSELL | 29 | 3NT | ♥6 | +3 | -2 |
| -3.1 | Round 8 | CANADA SENIORS | 27 | 2NT | ♥7 | = | +0 |
| -3.1 | Round 10 | MILNER | 11 | 3♣ | ♣9 | +2 | -1 |
| -3.2 | Round 3 | MARKOWICZ | 1 | 3NT | ♠8 | +1 | -7 |
| -3.9 | Round 10 | MILNER | 16 | 3NT | ♠4 | -1 | -6 |
| -4.8 | Round 5 | USARUSSELL | 27 | 4♥ | ♠6 | -2 | -11 |
| -4.9 | Round 5 | USARUSSELL | 23 | 2♠ | ♣K | +1 | -7 |
| -5.9 | Round 5 | USARUSSELL | 26 | 2NT | ♥10 | +1 | -10 |
| -6.1 | Round 3 | MARKOWICZ | 8 | 4♠ | ♥9 | -2 | -6 |
| -7.4 | Round 8 | CANADA SENIORS | 22 | 3NT | ♥6 | +1 | -1 |
| -8.3 | Round 6 | LEWIS | 1 | 3NT | ♥4 | +1 | -8 |
| -8.7 | Round 3 | MARKOWICZ | 7 | 3NT | ♥10 | = | +0 |
| -11.5 | Round 6 | LEWIS | 8 | 6♣ | ♠8 | +1 | +11 |