From olli.heimo at luukku.com Thu Feb 14 02:15:01 2019 From: olli.heimo at luukku.com (Olli Heimo) Date: Thu, 14 Feb 2019 09:15:01 +0200 (EET) Subject: [Retros] 1468 last moves Message-ID: <1550128501206.olli.heimo.88.e650CDIxvJ_wkXgrgZ3WHQ@luukku.com> Happy Valentine's day. One month ago I mailed here a position with 1462 duplex-retromoves. I wrote that very likely that record will soon been improved. Here are 1468 duplex-retromoves if I counted correctly. http://www.janko.at/Retros/d.php?ff=KB1QQ1Bk/1Q4q1/Q6q/2Q2q2/Q6Q/R7/Q6q/b1qqqq1b. In fen-order from a8 to h1: White 3+37+74+74+32+102+72+120+72+78+42+72=778 and Black 3+102+72+126+78+29+54+69+69+59+29=690. Note that Bg8 must have made a capture and that Pc7xQb8=B is not possible. Olli. From olli.heimo at luukku.com Wed Feb 27 07:19:01 2019 From: olli.heimo at luukku.com (Olli Heimo) Date: Wed, 27 Feb 2019 14:19:01 +0200 (EET) Subject: [Retros] 1477 last moves Message-ID: <1551269941654.olli.heimo.126606.KcvFqEPwNaGCBf5AwdU1Ww@luukku.com> Hi! After P1361155 two weeks ago I arranged the 16 queens better. It left no space for an additional rook, but there was a hole on f8 for a knight. Though on eighth rank, it must surprisingly be a black knight. In this new version I count 1477 last moves. http://www.janko.at/Retros/d.php?ff=KB1QQnBk/1Q4q1/Q6q/2Q2q2/Q6q/q6q/3QQ3/bq4qb. In fen-order from a8 to h1: White 3+42+69+64+43+96+66+114+78+102+102=779 and Black 20+3+89+66+114+78+60+60+30+74+74+30=698. Note illegal retractions Pc7xQb8=B and Qf6xBg7. In December I wrote that I assume about 1500 being possible. I don't no more believe on 1500 but who knows. Placing kings, 8+8 queens and 4-5 minor pieces on the board gives in the range of 10E30 possibilities. If a fast computer checks 10E10 positions per second it will take billions of years. Olli.