when the spring comes (NEW 2v16 LENGTH RECORD ?!)

[Hobacle]

[fen]7Q/4k2K/2P5/3P4/1P1P1Pq1/P2P1RP1/8/1NN2RBB b - - 0 0[/fen]
After 0...Kf7(I'm too tired to create another .pgn):
[pgn][Event ""]
[Site ""]
[Date "2021.09.14"]
[Round ""]
[White ""]
[Black ""]
[Result "0-1"]
[FEN "7Q/5k1K/2P5/3P4/1P1P1Pq1/P2P1RP1/8/1NN2RBB w - - 0 1"]
[SetUp "1"]

1. Qe8+ Kxe8 2. Re3+ Kf7 3. Re7+ Kxe7 4. Bf3 Qf5+ 5. Kh6 Kf6 6. Bh5 Qc8 7. Bg6
Qh3+ 8. Bh5 Qxg3 9. Be8 Qh3+ 10. Bh5 Qxf1 11. Ne2 Qg2 12. Be8 Qg8 13. Kh5 Qxe8+
14. Kh4 Qxe2 15. c7 Qe1+ 16. Kh3 Qf1+ 17. Kh2 Qxf4+ 18. Kg2 Qxc7 19. Nd2 Qc2
20. Be3 Qxd3 21. Kf3 Qf5+ 22. Bf4 Qxd5+ 23. Ke3 Kf5 24. Be5 Qa2 25. Kd3 Qb2 26.
Bd6 Qxa3+ 27. Kc2 Qa2+ 28. Kc3 Qa1+ 29. Kc4 Qa6+ 30. Kc5 Qc8+ 31. Kd5 Qg8+ 32.
Kc5 Ke6 33. d5+ Kd7 34. Be5 Qf8+ 35. Kb5 Qf7 36. Kc4 Qe7 37. Kd4 Qxb4+ 38. Nc4
Kc8 39. Bd6 Qa4 40. Be5 Kb7 41. Kc5 Ka6 42. Bc7 Qb5+ 43. Kd4 Qb4 44. Bd6 Qb1
45. Be5 Qd1+ 46. Ke4 Qa4 47. Kd3 Kb5 48. Ne3 Kc5 49. Bg7 Qh4 50. Bc3 Qh7+ 51.
Ke2 Qe4 52. Bf6 Kd6 53. Kd2 Kd7 54. Ke2 Ke8 55. Bc3 Kf7 56. Kf2 Kg6 57. Ba5 Kf6
58. Bc7 Ke7 59. Ba5 Qd4 60. Kf3 Kd7 61. Be1 Kc7 62. Bg3+ Kb7 63. Bd6 Ka6 64.
Bg3 Kb5 65. Bf4 Qh8 66. Ke4 Qh7+ 67. Kd4 Qh4 68. Ke5 Kc5 69. d6 Qh8+ 70. Kf5
Qc8+ 71. Ke5 Qe8+ 72. Kf5 Kd4 73. Ng4 Qc8+ 74. Kg5 Kd5 75. Kh4 Ke4 76. d7 Qh8+
77. Kg3 Kf5 78. Ne3+ Ke6 79. d8=Q Qxd8 80. Kf3 Qa8+ 81. Kf2 Qb7 82. Ke2 Qh1 83.
Kf2 Qh5 84. Bg3 Qf7+ 85. Ke2 Qf6 86. Be1 Qe5 87. Kd3 Qb5+ 88. Kd4 Qb6+ 89. Kd3
Qb1+ 90. Kd2 Ke5 91. Nc2 Ke4 92. Bf2 Qf1 93. Bd4 Qf4+ 94. Kc3 Qg5 95. Bb6 Qb5
96. Bd4 Qd3+ 97. Kb2 Qc4 98. Bc3 Qe2 99. Kb3 Qd1 100. Kb2 Kd3 101. Ne1+ Kc4
102. Ba5 Qd5 103. Bc3 Qb5+ 104. Kc2 Qb3+ 105. Kd2 Qxc3+ 106. Ke2 Kd4 107. Nf3+
Ke4 108. Nd2+ Kf4 109. Nb1 Qb3 110. Kd2 Qxb1 111. Kc3 Qb5 112. Kd4 Kf3 113. Kc3
Ke3 114. Kc2 Qb4 115. Kc1 Kd3 116. Kd1 Qb1# 0-1
[/pgn]

After 37...Qxb4+ tablebases help me to get the exact DTM, but I'm not sure about the previous moves. Quite need help to check it! Thanks!
P.S. Maybe moving a3 pawn to a2 won't change the DTM?

[mhouppin]

[fen]7Q/4k2K/2P5/3P4/1P1P1Pq1/P2P1RP1/8/1NN2RBB b - - 0 0[/fen]
After 0...Kf7(I'm too tired to create another .pgn):
[pgn][Event ""]
[Site ""]
[Date "2021.09.14"]
[Round ""]
[White ""]
[Black ""]
[Result "0-1"]
[FEN "7Q/5k1K/2P5/3P4/1P1P1Pq1/P2P1RP1/8/1NN2RBB w - - 0 1"]
[SetUp "1"]

1. Qe8+ Kxe8 2. Re3+ Kf7 3. Re7+ Kxe7 4. Bf3 Qf5+ 5. Kh6 Kf6 6. Bh5 Qc8 7. Bg6
Qh3+ 8. Bh5 Qxg3 9. Be8 Qh3+ 10. Bh5 Qxf1 11. Ne2 Qg2 12. Be8 Qg8 13. Kh5 Qxe8+
14. Kh4 Qxe2 15. c7 Qe1+ 16. Kh3 Qf1+ 17. Kh2 Qxf4+ 18. Kg2 Qxc7 19. Nd2 Qc2
20. Be3 Qxd3 21. Kf3 Qf5+ 22. Bf4 Qxd5+ 23. Ke3 Kf5 24. Be5 Qa2 25. Kd3 Qb2 26.
Bd6 Qxa3+ 27. Kc2 Qa2+ 28. Kc3 Qa1+ 29. Kc4 Qa6+ 30. Kc5 Qc8+ 31. Kd5 Qg8+ 32.
Kc5 Ke6 33. d5+ Kd7 34. Be5 Qf8+ 35. Kb5 Qf7 36. Kc4 Qe7 37. Kd4 Qxb4+ 38. Nc4
Kc8 39. Bd6 Qa4 40. Be5 Kb7 41. Kc5 Ka6 42. Bc7 Qb5+ 43. Kd4 Qb4 44. Bd6 Qb1
45. Be5 Qd1+ 46. Ke4 Qa4 47. Kd3 Kb5 48. Ne3 Kc5 49. Bg7 Qh4 50. Bc3 Qh7+ 51.
Ke2 Qe4 52. Bf6 Kd6 53. Kd2 Kd7 54. Ke2 Ke8 55. Bc3 Kf7 56. Kf2 Kg6 57. Ba5 Kf6
58. Bc7 Ke7 59. Ba5 Qd4 60. Kf3 Kd7 61. Be1 Kc7 62. Bg3+ Kb7 63. Bd6 Ka6 64.
Bg3 Kb5 65. Bf4 Qh8 66. Ke4 Qh7+ 67. Kd4 Qh4 68. Ke5 Kc5 69. d6 Qh8+ 70. Kf5
Qc8+ 71. Ke5 Qe8+ 72. Kf5 Kd4 73. Ng4 Qc8+ 74. Kg5 Kd5 75. Kh4 Ke4 76. d7 Qh8+
77. Kg3 Kf5 78. Ne3+ Ke6 79. d8=Q Qxd8 80. Kf3 Qa8+ 81. Kf2 Qb7 82. Ke2 Qh1 83.
Kf2 Qh5 84. Bg3 Qf7+ 85. Ke2 Qf6 86. Be1 Qe5 87. Kd3 Qb5+ 88. Kd4 Qb6+ 89. Kd3
Qb1+ 90. Kd2 Ke5 91. Nc2 Ke4 92. Bf2 Qf1 93. Bd4 Qf4+ 94. Kc3 Qg5 95. Bb6 Qb5
96. Bd4 Qd3+ 97. Kb2 Qc4 98. Bc3 Qe2 99. Kb3 Qd1 100. Kb2 Kd3 101. Ne1+ Kc4
102. Ba5 Qd5 103. Bc3 Qb5+ 104. Kc2 Qb3+ 105. Kd2 Qxc3+ 106. Ke2 Kd4 107. Nf3+
Ke4 108. Nd2+ Kf4 109. Nb1 Qb3 110. Kd2 Qxb1 111. Kc3 Qb5 112. Kd4 Kf3 113. Kc3
Ke3 114. Kc2 Qb4 115. Kc1 Kd3 116. Kd1 Qb1# 0-1
[/pgn]

After 37...Qxb4+ tablebases help me to get the exact DTM, but I'm not sure about the previous moves. Quite need help to check it! Thanks!
P.S. Maybe moving a3 pawn to a2 won't change the DTM?

I tried analysing the position with Stash, and I stumbled on a potential draw on move 10: what if Black plays Qg3 instead of Qxf1 ?
Then 11. Be8 Qh4+ 12. Bh5 Qg3 and Black has a forced repetition...

[Hobacle]

I tried analysing the position with Stash, and I stumbled on a potential draw on move 10: what if Black plays Qg3 instead of Qxf1 ?
Then 11. Be8 Qh4+ 12. Bh5 Qg3 and Black has a forced repetition...

As you can see Black is able to win, so it's not surprising to see a forced draw made by himself.

[Hobacle]

Longest KRv16(a bit hard for engines, also a great challenge for humans):

[fen]7n/n2ppp2/3p4/8/R6b/8/3pp1pp/1K1krbrq w - - 0 1[/fen]

[peter]

[fen]7Q/4k2K/2P5/3P4/1P1P1Pq1/P2P1RP1/8/1NN2RBB b - - 0 0[/fen]
After 0...Kf7(I'm too tired to create another .pgn):
[pgn][Event ""]
[Site ""]
[Date "2021.09.14"]
[Round ""]
[White ""]
[Black ""]
[Result "0-1"]
[FEN "7Q/5k1K/2P5/3P4/1P1P1Pq1/P2P1RP1/8/1NN2RBB w - - 0 1"]
[SetUp "1"]

1. Qe8+ Kxe8 2. Re3+ Kf7 3. Re7+ Kxe7 4. Bf3 Qf5+ 5. Kh6 Kf6 6. Bh5 Qc8 7. Bg6
Qh3+ 8. Bh5 Qxg3 9. Be8 Qh3+ 10. Bh5 Qxf1 11. Ne2 Qg2 12. Be8 Qg8 13. Kh5 Qxe8+
14. Kh4 Qxe2 15. c7 Qe1+ 16. Kh3 Qf1+ 17. Kh2 Qxf4+ 18. Kg2 Qxc7 19. Nd2 Qc2
20. Be3 Qxd3 21. Kf3 Qf5+ 22. Bf4 Qxd5+ 23. Ke3 Kf5 24. Be5 Qa2 25. Kd3 Qb2 26.
Bd6 Qxa3+ 27. Kc2 Qa2+ 28. Kc3 Qa1+ 29. Kc4 Qa6+ 30. Kc5 Qc8+ 31. Kd5 Qg8+ 32.
Kc5 Ke6 33. d5+ Kd7 34. Be5 Qf8+ 35. Kb5 Qf7 36. Kc4 Qe7 37. Kd4 Qxb4+ 38. Nc4
Kc8 39. Bd6 Qa4 40. Be5 Kb7 41. Kc5 Ka6 42. Bc7 Qb5+ 43. Kd4 Qb4 44. Bd6 Qb1
45. Be5 Qd1+ 46. Ke4 Qa4 47. Kd3 Kb5 48. Ne3 Kc5 49. Bg7 Qh4 50. Bc3 Qh7+ 51.
Ke2 Qe4 52. Bf6 Kd6 53. Kd2 Kd7 54. Ke2 Ke8 55. Bc3 Kf7 56. Kf2 Kg6 57. Ba5 Kf6
58. Bc7 Ke7 59. Ba5 Qd4 60. Kf3 Kd7 61. Be1 Kc7 62. Bg3+ Kb7 63. Bd6 Ka6 64.
Bg3 Kb5 65. Bf4 Qh8 66. Ke4 Qh7+ 67. Kd4 Qh4 68. Ke5 Kc5 69. d6 Qh8+ 70. Kf5
Qc8+ 71. Ke5 Qe8+ 72. Kf5 Kd4 73. Ng4 Qc8+ 74. Kg5 Kd5 75. Kh4 Ke4 76. d7 Qh8+
77. Kg3 Kf5 78. Ne3+ Ke6 79. d8=Q Qxd8 80. Kf3 Qa8+ 81. Kf2 Qb7 82. Ke2 Qh1 83.
Kf2 Qh5 84. Bg3 Qf7+ 85. Ke2 Qf6 86. Be1 Qe5 87. Kd3 Qb5+ 88. Kd4 Qb6+ 89. Kd3
Qb1+ 90. Kd2 Ke5 91. Nc2 Ke4 92. Bf2 Qf1 93. Bd4 Qf4+ 94. Kc3 Qg5 95. Bb6 Qb5
96. Bd4 Qd3+ 97. Kb2 Qc4 98. Bc3 Qe2 99. Kb3 Qd1 100. Kb2 Kd3 101. Ne1+ Kc4
102. Ba5 Qd5 103. Bc3 Qb5+ 104. Kc2 Qb3+ 105. Kd2 Qxc3+ 106. Ke2 Kd4 107. Nf3+
Ke4 108. Nd2+ Kf4 109. Nb1 Qb3 110. Kd2 Qxb1 111. Kc3 Qb5 112. Kd4 Kf3 113. Kc3
Ke3 114. Kc2 Qb4 115. Kc1 Kd3 116. Kd1 Qb1# 0-1
[/pgn]

After 37...Qxb4+ tablebases help me to get the exact DTM, but I'm not sure about the previous moves. Quite need help to check it! Thanks!
P.S. Maybe moving a3 pawn to a2 won't change the DTM?

After 27...Qxa3+ (26... in your .pgn without 1.move) it's -#90:

8/8/3B4/5k2/1P1P4/q2K4/3N4/8 w - - 0 28

1.Kc2 Qa2+ 2.Kc3 Qa1+ 3.Kc4 Qa6+ 4.Kc5 Qc8+ 5.Kd5 Qg8+ 6.Kc5 Ke6 7.d5+ Kd7 8.
Be5 Qf8+ 9.Kb5 Qf7 10.Kc4 Qe7 11.Kd4 Qxb4+ 12.Nc4 Kc8 13.Bd6 Qa4 14.Be5 Kb7 15.
Kc5 Ka6 16.Bc7 Qb5+ 17.Kd4 Qb4 18.Bd6 Qb1 19.Be5 Qd1+ 20.Ke4 Qa4 21.Kd3 Kb5 22.
Ne3 Kc5 23.Bc3 Qh4 24.Ba1 Qh7+ 25.Kd2 Qe4 26.Bb2 Kd6 27.Bf6 Kd7 28.Bc3 Ke7 29.
Ke2 Kf7 30.Kf2 Kg6 31.Ba5 Qd4 32.Bc7 Kf7 33.Bg3 Ke7 34.Bc7 Kd7 35.Bg3 Kc8 36.
Ke2 Kb7 37.Bd6 Kb6 38.Kf3 Kb5 39.Bf4 Qg7 40.Ke4 Qh7+ 41.Kd4 Qh4 42.Ke5 Kc5 43.
d6 Qh5+ 44.Nf5 Kc6 45.Kf6 Kd7 46.Ne3 Qc5 47.Nf5 Qd5 48.Ng3 Qe6+ 49.Kg5 Qg8+ 50.
Kf5 Qe8 51.Be5 Qf8+ 52.Ke4 Qf2 53.Nf5 Qc2+ 54.Kf4 Qh2+ 55.Ke4 Qh7 56.Kf4 Ke6
57.Nd4+ Kd5 58.Nf3 Qa7 59.Bc3 Qa4+ 60.Ke3 Qe4+ 61.Kf2 Qc2+ 62.Bd2 Ke4 63.d7
Qc5+ 64.Kg2 Qd5 65.Be1 Qxd7 66.Nh2 Qe6 67.Bf2 Kf5 68.Bg3 Qe2+ 69.Kh3 Kg6 70.
Bh4 Qh5 71.Kg3 Kf5 72.Nf3 Qh6 73.Bg5 Qg7 74.Kf2 Kg4 75.Ke2 Qb2+ 76.Nd2 Kxg5 77.
Kd3 Kf4 78.Nc4 Qh8 79.Nd2 Qh3+ 80.Kc4 Qe3 81.Nb3 Ke5 82.Na5 Qd4+ 83.Kb5 Kd5 84.
Nb7 Qb2+ 85.Ka6 Kc6 86.Nd8+ Kd7 87.Nf7 Qb4 88.Ne5+ Kc7 89.Nc4 Qc5 90.Nb6 Qxb6#

As for the rest of the moves you should ask somebody, who has already downloaded this one 7men- position to disk

[peter]

Longest KRv16(a bit hard for engines, also a great challenge for humans):

[fen]7n/n2ppp2/3p4/8/R6b/8/3pp1pp/1K1krbrq w - - 0 1[/fen]

No problem for SlowChess having had a little Forward- Backward:

7n/n2ppp2/3p4/8/R6b/8/3pp1pp/1K1krbrq w - - 0 1

Analysis by SlowChess Blitz 2.7 avx:

1.Rxh4 Nb5 2.Kb2 Na3 3.Ra4 Nc2 4.Rc4 Ne3 5.Rc3 Ng6 6.Rxe3 Ne5 7.Re4 Nd3+ 8.Kb1 Ne5 9.Ra4 d5 10.Ra2 Nc4 11.Ra1 e6 12.Ra6 Ne5 13.Ra4 Nd3 14.Ra1 e5 15.Ra5 e4 16.Ra1 d6 17.Ra5 Ne5 18.Ra3 Nc4 19.Ra1 e3 20.Ra6 Ne5 21.Ra4 Nd3 22.Ra1 d4 23.Ra7 Ne5 24.Ra3 Nc4 25.Ra1 f6 26.Ra7 Ne5 27.Ra3 Nc4 28.Ra1 f5 29.Ra2 Ne5 30.Ra3 Nc4 31.Ra1 f4 32.Ra6 Ne5 33.Ra3 Nc4 34.Ra1 f3 35.Ra6 Ne5 36.Ra7 Nc4 37.Ra1 d5 38.Ra4 Nb6 39.Ra2 Nc4 40.Ra1 f2 41.Ra6 Ne5 42.Ra3 d3 43.Ra4 Nc4 44.Ra2 Na3+ 45.Kb2 Nc2 46.Ra5 d4 47.Ra2 Na3 48.Ra1+ Nb1 49.Rxb1#
+- (#49) Depth: 92/106 00:00:44 1422MN, tb=4830

Edit: for SF11 neither, even started with empty hash (so probably that would have worked with SlowChess too, didn't try, just started with FW-BW then at once), and even one move less DTM:

7n/n2ppp2/3p4/8/R6b/8/3pp1pp/1K1krbrq w - - 0 1

Analysis by Stockfish 11 64 POPCNT:

1.Rxh4 Nb5 2.Kb2 Na3 3.Ra4 Nc2 4.Rc4 Ne3 5.Rc3 Ng6 6.Rxe3 Ne5 7.Re4 Nd3+ 8.Kb1 Ne5 9.Ra4 d5 10.Ra8 Nd3 11.Ra1 f6 12.Ra7 Ne5 13.Kb2 Nd3+ 14.Kc3 d4+ 15.Kb3 Nc5+ 16.Kb2 Nd3+ 17.Kb1 Ne5 18.Rc7 e6 19.Ra7 Nc4 20.Ra1 f5 21.Ra6 e5 22.Ra7 e4 23.Ra1 d6 24.Ra2 Ne5 25.Ra4 Nd3 26.Ra1 d5 27.Ra4 Ne5 28.Ra3 Nc4 29.Ra1 f4 30.Ra7 Ne5 31.Ra6 Nd3 32.Ra1 f3 33.Ra8 Nf2 34.Ra3 Nd3 35.Ra1 f2 36.Ra5 Nc1 37.Ra7 Nd3 38.Ra1 e3 39.Ra3 Ne5 40.Ra4 Nd3 41.Ra1 Nc1 42.Kb2 d3 43.Ra4 d4 44.Rxd4 Na2 45.Ra4 Nc1 46.Kc3 Nb3 47.Kxb3 Kc1 48.Ra1#
+- (#48) Depth: 118/96 00:02:27 14738MN

[Hobacle]

Longest KRv16(a bit hard for engines, also a great challenge for humans):

[fen]7n/n2ppp2/3p4/8/R6b/8/3pp1pp/1K1krbrq w - - 0 1[/fen]

for SF11 neither, even started with empty hash (so probably that would have worked with SlowChess too, didn't try, just started with FW-BW then at once), and even one move less DTM:

7n/n2ppp2/3p4/8/R6b/8/3pp1pp/1K1krbrq w - - 0 1

Analysis by Stockfish 11 64 POPCNT:

1.Rxh4 Nb5 2.Kb2 Na3 3.Ra4 Nc2 4.Rc4 Ne3 5.Rc3 Ng6 6.Rxe3 Ne5 7.Re4 Nd3+ 8.Kb1 Ne5 9.Ra4 d5 10.Ra8 Nd3 11.Ra1 f6 12.Ra7 Ne5 13.Kb2 Nd3+ 14.Kc3 d4+ 15.Kb3 Nc5+ 16.Kb2 Nd3+ 17.Kb1 Ne5 18.Rc7 e6 19.Ra7 Nc4 20.Ra1 f5 21.Ra6 e5 22.Ra7 e4 23.Ra1 d6 24.Ra2 Ne5 25.Ra4 Nd3 26.Ra1 d5 27.Ra4 Ne5 28.Ra3 Nc4 29.Ra1 f4 30.Ra7 Ne5 31.Ra6 Nd3 32.Ra1 f3 33.Ra8 Nf2 34.Ra3 Nd3 35.Ra1 f2 36.Ra5 Nc1 37.Ra7 Nd3 38.Ra1 e3 39.Ra3 Ne5 40.Ra4 Nd3 41.Ra1 Nc1 42.Kb2 d3 43.Ra4 d4 44.Rxd4 Na2 45.Ra4 Nc1 46.Kc3 Nb3 47.Kxb3 Kc1 48.Ra1#
+- (#48) Depth: 118/96 00:02:27 14738MN

OK, from my side SF11 gets #48 too. I haven't seen any way for White to win faster.
But it seems that #48 isn't enough to get applause. Although it's a record, only a few composers have worked on it.
And do you think people will admit the record of KQv16 with 90 moves under 7 pieces?

[peter]

And do you think people will admit the record of KQv16 with 90 moves under 7 pieces?

I really don't have any idea, dear Hobacle, but if I find anything longer then yours, you'll be the first one, I'll tell so.

If I ever have a second one reason to download the 7men- position i question, I'll give it a try to go backward from there with engine, yet it's not on my todo- list right now regards

[Hobacle]

And do you think people will admit the record of KQv16 with 90 moves under 7 pieces?

I really don't have any idea, dear Hobacle, but if I find anything longer then yours, you'll be the first one, I'll tell so.

http://superproblem.ru/index-en.html
According to the collection by superproblem.ru, the length record for KQv16 was #77, and the one for KRv16 was only #22.

[Hobacle]

No problem for SlowChess having had a little Forward- Backward:

What about this one?
7k/4p3/4p3/8/8/5pp1/P2Kprrb/4nbqn w - - 0 1
Is it winning for White? If yes, can you get the exact DTM?