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42P-63 data — Two Questions and a Correction

Posted By: Taper_Mike
Date: Thursday, 19 April 2012, at 3:13 a.m.

In Response To: 42P-63 data (Nack Ballard)

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42P-63 Question 1 As part of the data summary in the preceding post, Nack gives this nacbrac for an XG1 rollout of 42P-63: Money XG 3-ply [S R7] 15k At the root of this thread, David Rockwell posts his XG1 rollout of the same position: 42P-63 [S R1] '<46 It is odd that Nack does not include David’s rollout in his data summary. Are these two XG1 rollouts independent of each other (or do they share a common seed)? Has the 15k rollout ever been posted at BGO? Question 2 In the preceding post, Nack gives these AtS nacbracs for 42P-63: Other scores d[S R9] 5k s[R S22] 5k Nack accidentally omits the bot used in these at-score rollouts. Any clarification is appreciated. For these early posts, often the answer is GnuBg. That’s because XG was not as common back then, and the AtS Snowie data was faked, produced by mathematical adjustments to the money rollout. If you read carefully, you will see that Nack always points out that Snowie fakes its AtS data whenever he reports any. Since he does not provide any such disclaimer in his data summary, it is fair to conclude that the data are not from Snowie. So, that leaves GnuBg. Correction The two XG rollouts in this thread, the first by David, and the second by Neil, provide a case study in the transcription of nacbracs. In David’s rollout, XG reports absolute equities that are the same, yet the correct nacbrac shows R trailing by 0.001. Conversely, in Neil’s rollout, XG reports absolute equities that differ by 0.001, yet the correct nacbrac has S = R. See the tables below for the details.

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David’s 3-ply Rollout – 42P-63 [S R1] '<46

Play	Absolute Equity	Trails by	Note
S	–0.319	—	S is between –0.3185 and –0.3195.
R	–0.319	–0.001	R is between –0.3185 and –0.3195. R trails S by more than 0.0005, and less than 0.0015.
			Therefore, S is between –0.3185 and –0.3190, R is between –0.3190 and –0.3195, and R trails S by more than 0.0005 and less than 0.0010.

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Neil’s 4-ply Rollout – 42P-63 [S=R] '^46

Play	Absolute Equity	Trails by	Note
S	–0.317	—	S is between –0.3165 and –0.3175.
R	–0.318	[left blank by XG]	R is between –0.3175 and –0.3185. R trails S by less than 0.0005.
			Therefore, S is between –0.3170 and –0.3175, and R is between –0.3175 and –0.3180.

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In the preceding post, Nack fell into the trap of reporting XG’s absolute equites in his nacbrac for Neil’s 4-ply rollout. Nack erroneously reports 42P-63 [S R1] '<46. You can bet that is an error he would not make today. [Nack, have you already corrected your summary sheet?] The lesson here is to always use the difference reported by XG when forming a nacbrac. Do not subtract the absolute equities. Subtracting these rounded values is less accurate than accepting the subtraction that XG made using unrounded values. Mike

Messages In This Thread

• 42P-63 TCTC
  David Rockwell -- Sunday, 20 June 2010, at 6:40 p.m.
  • 42P-63 TCTC..I will 4 ply RO it
    neilkaz -- Sunday, 20 June 2010, at 6:57 p.m.
    • 42P-63 4ply 46k has been done
      neilkaz -- Sunday, 20 June 2010, at 7:10 p.m.
      • 42P-63 data
        Nack Ballard -- Monday, 21 June 2010, at 12:05 a.m.
        • 42P-63 data
          neilkaz -- Monday, 21 June 2010, at 5:09 a.m.
        • 42P-63 data — Two Questions and a Correction
          Taper_Mike -- Thursday, 19 April 2012, at 3:13 a.m.
          • 42P-63 data — Two Questions and a Correction
            Nack Ballard -- Sunday, 22 April 2012, at 3:17 a.m.
            • 42P-63 data — Two Questions and a Correction
              Nack Ballard -- Sunday, 22 April 2012, at 3:24 a.m.
              • 42P-63 data — Two Questions and a Correction
                Taper_Mike -- Sunday, 22 April 2012, at 4:21 a.m.
            • 42P-63 data — Two Questions and a Correction
              Taper_Mike -- Monday, 23 April 2012, at 4:37 a.m.