Joerg Oster wrote:I have seen this also at more shallow depths, so I don't think that's a good explanation.
And I never heard that by searching one or more plies deeper, maybe after implementing Null Move or LMR, an engine began to show more draw scores than before. Did you?
Maybe take a look at the below game, at the eval after move 52 for black.
[pgn][PlyCount "225"]
[MLNrOfMoves "112"]
[MLFlags "100100"]
[Date "2014.04.13"]
[Round "1"]
[White "Senpai 1.0"]
[Black "Stockfish 14041208"]
[Result "1-0"]
[EventDate "2014.??.??"]
[ECO "A49"]
[TimeControl "240+2"]
1. d4 {book} 1... Nf6 {book} 2. Nf3 {book} 2... g6 {book} 3. g3 {book} 3... Bg7
{book} 4. Bg2 {book} 4... c5 {book} 5. d5 {book} 5... O-O {book} 6. c4 {book}
6... d6 {book} 7. O-O {book} 7... b5 {book} 8. cxb5 {book} 8... a6 {book} 9.
bxa6 {+0.65/18 7.2s} 9... Bxa6 {-0.41/21 7.8s} 10. Nc3 {+0.72/20 8.0s} 10...
Nbd7 {-0.40/22 5.3s} 11. Qc2 {+0.72/20 28s} 11... Ng4 {-0.42/ 21 7.1s} 12. Rd1
{+0.90/18 6.1s} 12... Qb6 {-0.38/21 6.5s} 13. Bg5 {+0.93/17 7.0s} 13... Rfb8
{-0.37/22 10s} 14. Rab1 {+0.99/19 6.2s} 14... Qd8 {-0.38/23 5.4s} 15. h3
{+0.87/ 18 6.0s} 15... Nge5 {-0.37/24 5.4s} 16. Nxe5 {+0.87/20 6.5s} 16... Nxe5
{-0.37/24 5.5s} 17. b3 {+0.87/20 9.8s} 17... Bc8 {-0.37/24 5.6s} 18. Ne4
{+0.93/18 5.2s} 18... f5 {-0.36/22 14s} 19. Nc3 {+0.92/19 4.8s} 19... Bd7
{-0.35/23 5.6s} 20. Rdc1 {+0.91/19 4.9s} 20... Ra3 {-0. 30/21 11s} 21. Rb2
{+0.89/18 5.0s} 21... Nf7 {-0.22/22 10s} 22. Bd2 {+0.81/18 9.3s} 22... Rb7
{-0.22/21 5.6s} 23. Kf1 {+0.78/17 6.0s} 23... Qa8 {-0.23/22 16s} 24. Ra1
{+0.77/ 18 9.8s} 24... Qa6 {-0.23/21 5.5s} 25. Kg1 {+0.77/19 7.5s} 25... Bd4
{-0.23/21 11s} 26. e3 {+0.90/19 5.3s} 26... Bg7 {-0.24/21 8.9s} 27. f4
{+0.93/18 4.7s} 27... Rb8 {-0.31/18 8.7s} 28. Bf1 {+0.90/19 5.4s} 28... Qb7
{-0.37/21 14s} 29. Bc4 {+0.90/19 5.1s} 29... Re8 {-0.52/ 23 18s} 30. Re1
{+0.94/19 5.0s} 30... e5 {-0.31/21 16s} 31. Rbb1 {+1.13/16 4.3s} 31... Qa8
{-0.56/22 26s} 32. Rbd1 {+1.12/18 4.9s} 32... Qa5 {-0.53/21 11s} 33. Bd3
{+1.16/18 7. 9s} 33... Qb6 {-0.51/20 5.6s} 34. Kg2 {+1.13/18 3.8s} 34... e4
{-0.59/20 8.7s} 35. Bc4 {+1. 32/20 5.5s} 35... Qa5 {-0.68/24 9.8s} 36. Re2
{+1.43/21 3.9s} 36... Qb6 {-0.81/26 11s} 37. Bc1 {+1.44/22 4.0s} 37... Raa8
{-0.81/26 3.5s} 38. a4 {+1.46/21 4.7s} 38... Re7 {-0.85/24 7.0s} 39. Bb2
{+1.45/21 4.3s} 39... Nd8 {-0.88/24 5.7s} 40. Nb5 {+1.41/21 6.3s} 40... Nb7
{-0.87/25 3.4s} 41. Bxg7 {+1.42/21 4.3s} 41... Rxg7 {-0.87/22 5.7s} 42. Rf2
{+1.41/22 5.1s} 42... g5 {-0.74/21 8.8s} 43. fxg5 {+1.68/19 4.2s} 43... Rxg5
{-1.07/21 4.3s} 44. Qc3 {+1.75/19 5.1s} 44... Rg7 {-0.82/21 9.4s} 45. Kh2
{+1.72/19 3.9s} 45... Nd8 {-0.75/22 7.8s} 46. Be2 {+1.44/20 4.5s} 46... Nf7
{-0.86/23 4.2s} 47. Na3 {+1.36/22 4.9s} 47... Ne5 {-0.86/ 23 2.3s} 48. Nc4
{+1.36/21 1.8s} 48... Nxc4 {-0.96/24 11s} 49. Bxc4 {+1.38/20 5.2s} 49... Qd8
{-0.90/23 4.6s} 50. Rdf1 {+1.38/20 4.2s} 50... h6 {-0.89/21 5.1s} 51. Rg2
{+1.41/ 19 3.5s} 51... Kh7 {-0.86/21 2.2s} 52. Rgf2 {+1.31/20 27s} 52... Kg8
{0.00/35 2.3s} 53. Rf4 {+1.38/18 3.2s} 53... Kh7 {-0.79/21 2.4s} 54. Qe1
{+1.32/17 2.9s} 54... Qg5 {-0.79/20 3.2s} 55. Rg1 {+1.41/20 3.4s} 55... Qf6
{-0.82/21 1.5s} 56. Qa1 {+1.35/19 16s} 56... Qd8 {-0.81/ 22 1.5s} 57. Qb1
{+1.31/20 3.2s} 57... Qg5 {-0.80/20 3.5s} 58. Rg2 {+1.38/19 3.2s} 58... Qe7
{-0.81/21 3.1s} 59. Qb2 {+1.31/19 2.7s} 59... Qf7 {-0.85/21 1.3s} 60. Qa1
{+1.37/ 18 7.0s} 60... Qg6 {-0.85/22 2.3s} 61. Qf1 {+1.41/16 2.7s} 61... Qf7
{-0.82/23 3.6s} 62. Qf2 {+1.31/18 6.2s} 62... Qe7 {-0.82/22 1.3s} 63. Bb5
{+1.41/20 2.6s} 63... Bc8 {-0.95/23 3.5s} 64. Qb2 {+1.41/21 4.5s} 64... Rb8
{-1.04/20 2.4s} 65. Qc3 {+1.41/21 4.1s} 65... Bd7 {-0.98/19 2.4s} 66. Bxd7
{+1.38/20 3.7s} 66... Qxd7 {-1.18/21 2.4s} 67. Qc4 {+1.42/20 3.3s} 67... Rb4
{-1.11/19 2.4s} 68. Qc2 {+1.25/20 2.7s} 68... Qf7 {-1.25/20 2.4s} 69. Qd1
{+1.46/20 3.6s} 69... Qf6 {-1.17/19 2.1s} 70. a5 {+1.71/17 5.0s} 70... Qc3
{-1.44/20 2.7s} 71. Qh5 {+1.66/19 2.6s} 71... Qf6 {-1.44/22 2.4s} 72. Rxf5
{+2.09/20 4.4s} 72... Qg6 {-1. 37/22 1.8s} 73. Qxg6+ {+1.81/20 1.2s} 73... Kxg6
{-1.59/24 3.0s} 74. Rgf2 {+1.80/23 6.9s} 74... Rxb3 {-1.70/19 2.0s} 75. Rf6+
{+1.90/17 2.9s} 75... Kh7 {-1.46/20 1.5s} 76. Rxd6 {+1.73/19 3.9s} 76... Rxe3
{-1.84/20 3.7s} 77. g4 {+1.80/20 2.6s} 77... Rb7 {-1.84/20 2.4s} 78. Rb6
{+2.18/19 3.0s} 78... Rd7 {-1.84/20 1.3s} 79. d6 {+2.24/19 3.0s} 79... Ra3
{-2.36/21 3.5s} 80. a6 {+2.79/16 3.2s} 80... Kg6 {-2.22/21 1.7s} 81. Rc2
{+2.78/17 2. 7s} 81... h5 {-2.29/20 3.0s} 82. gxh5+ {+3.48/16 2.7s} 82... Kxh5
{-2.55/20 2.4s} 83. Rxc5+ {+3.36/18 1.5s} 83... Kh4 {-2.91/20 2.0s} 84. Rc7
{+3.64/18 4.1s} 84... Ra2+ {-4.26/20 2.8s} 85. Kg1 {+4.05/20 4.9s} 85... Rd8
{-4.48/22 2.3s} 86. a7 {+4.17/17 4.7s} 86... Kxh3 {-4. 61/22 2.5s} 87. Rb8
{+4.83/20 3.5s} 87... Rxd6 {-5.14/25 2.4s} 88. Rh7+ {+5.44/20 2. 4s} 88... Kg4
{-5.60/22 2.1s} 89. Rg7+ {+5.59/21 4.2s} 89... Kf5 {-5.68/23 2.6s} 90. Rf8+
{+5.70/19 3.9s} 90... Ke6 {-5.72/26 2.5s} 91. Rg6+ {+5.90/20 4.2s} 91... Ke5
{-5.72/27 1.3s} 92. Re8+ {+5.96/20 2.5s} 92... Kf4 {-5.84/27 3.2s} 93. Rxd6
{+5.98/21 3.8s} 93... Rxa7 {-5. 84/28 1.4s} 94. Rd4 {+5.99/18 2.4s} 94... Ra1+
{-5.90/28 3.7s} 95. Kf2 {+6.01/22 4.1s} 95... Ra2+ {-5.95/28 1.3s} 96. Ke1
{+6.09/17 2.1s} 96... Ra1+ {-5.95/27 2.4s} 97. Kd2 {+6.11/22 4.0s} 97... Ra2+
{-16.57/26 3.5s} 98. Kc3 {+6.13/22 3.9s} 98... Re2 {-9.40/26 2.4s} 99. Kc4
{+6.21/23 3.8s} 99... Kf5 {-22.41/22 1.9s} 100. Kd5 {+6.36/17 2.6s} 100... e3
{-27.41/27 2.8s} 101. Rf8+ {+10.07/21 3.7s} 101... Kg6 {-101.33/32 2.4s} 102.
Rg4+ {+M23/17 5.5s} 102... Kh7 {-M38/23 1.9s} 103. Rf3 {+M21/17 2.8s} 103... Rh2
{-M28/24 2.2s} 104. Rxe3 {+M19/15 0.97s} 104... Rh6 {-M18/25 2.3s} 105. Re7+
{+M17/15 0.92s} 105... Kh8 {-M16/1 0s} 106. Rc4 {+M15/17 2.7s} 106... Rg6
{-M14/30 1.7s} 107. Rc8+ {+M13/20 2.5s} 107... Rg8 {-M12/1 0s} 108. Rxg8+
{+M11/36 0.89s} 108... Kxg8 {-M10/1 0s} 109. Ke6 {+M9/99 0. 25s} 109... Kf8
{-M8/120 0.063s} 110. Kf6 {+M7/99 0s} 110... Kg8 {-M6/1 0s} 111. Re8+
{+M5/ 99 0s} 111... Kh7 {-M4/1 0s} 112. Rd8 {+M3/99 0s} 112... Kh6 {-M2/1 0s}
113. Rh8# {+M1/99 0s, White mates} 1-0
[/pgn]
SF expects draw by repetition after the first repetition that occurs in the position and returns 0.0 instead of the objective best move and score.