Simex | Rebel

Comparing similarity / originality between the Top-20 engines during the period of one year.

For the purpose we are using SIMEX, a tool that measures move similarities between engines using 8238 selected positions playing on depth=1, meaning that the main search is canceled and we mainly testing the evaluation of engines whether HCE or NNUE.

Situation August 2023

The then current top engines

Situation August 2024

A wave of new engines stormed the rating lists

We measured the similarity / originality of these engines ALSO with SIMEX.

And suddenly we get :

39. Engine motor-060 and Obsidian-11 show a similarity of 66.37%
43. Engine motor-060 and Obsidian-10 show a similarity of 66.07%
44. Engine motor-050 and Obsidian-11 show a similarity of 66.04%
45. Engine motor-060 and Obsidian-9 show a similarity of 66.04%
46. Engine stormphrax-4.1 and viridithas-12 show a similarity of 65.79%
51. Engine stormphrax-4.0 and viridithas-12 show a similarity of 65.59%
56. Engine stormphrax-4.1 and viridithas-11 show a similarity of 65.47%
58. Engine motor-050 and Obsidian-10 show a similarity of 65.35%
59. Engine motor-050 and Obsidian-9 show a similarity of 65.33%
60. Engine stormphrax-4.0 and viridithas-11 show a similarity of 65.29%
75. Engine stormphrax-4.1 and viridithas-10 show a similarity of 63.01%
77. Engine Obsidian-11 and PlentyChess-1.0.0 show a similarity of 62.86%
79. Engine motor-060 and PlentyChess-2.1.0 show a similarity of 62.83%
81. Engine stormphrax-4.0 and viridithas-10 show a similarity of 62.77%
82. Engine stormphrax-5.0 and viridithas-13 show a similarity of 62.66%
83. Engine Obsidian-11 and PlentyChess-2.1.0 show a similarity of 62.61%
84. Engine Obsidian-12 and PlentyChess-2.1.0 show a similarity of 62.57%
85. Engine Obsidian-10 and PlentyChess-1.0.0 show a similarity of 62.53%
87. Engine Obsidian-9 and PlentyChess-1.0.0 show a similarity of 62.52%
88. Engine stormphrax-5.0 and viridithas-12 show a similarity of 62.39%
90. Engine Obsidian-10 and PlentyChess-2.1.0 show a similarity of 62.32%
91. Engine Obsidian-9 and PlentyChess-2.1.0 show a similarity of 62.32%
93. Engine Obsidian-11 and viridithas-11 show a similarity of 62.24%
94. Engine stormphrax-5.0 and viridithas-11 show a similarity of 62.13%
97. Engine Clarity-6.0 and viridithas-11 show a similarity of 62.01%
98. Engine Clarity-7.2 and motor-060 show a similarity of 61.99%
101. Engine motor-050 and viridithas-11 show a similarity of 61.86%
103. Engine motor-040 and PlentyChess-0.3.0 show a similarity of 61.84%
104. Engine motor-060 and PlentyChess-1.0.0 show a similarity of 61.81%
105. Engine Obsidian-10 and viridithas-11 show a similarity of 61.77%
106. Engine Obsidian-9 and viridithas-11 show a similarity of 61.75%
107. Engine Clarity-7.2 and PlentyChess-2.1.0 show a similarity of 61.73%
111. Engine Obsidian-11 and PlentyChess-0.3.0 show a similarity of 61.65%
112. Engine motor-050 and PlentyChess-0.3.0 show a similarity of 61.44%
113. Engine Obsidian-10 and PlentyChess-0.3.0 show a similarity of 61.41%
114. Engine Obsidian-9 and PlentyChess-0.3.0 show a similarity of 61.38%
117. Engine Clarity-7.2 and Obsidian-11 show a similarity of 61.19%
119. Engine stormphrax-4.1 and viridithas-13 show a similarity of 61.18%
120. Engine stormphrax-4.0 and viridithas-13 show a similarity of 61.15%
121. Engine motor-040 and Obsidian-11 show a similarity of 61.14%
127. Engine Lizard-10.2 and Obsidian-11 show a similarity of 60.93%
129. Engine motor-050 and PlentyChess-2.1.0 show a similarity of 60.84%
130. Engine motor-060 and viridithas-11 show a similarity of 60.81%
131. Engine motor-040 and Obsidian-10 show a similarity of 60.79%
132. Engine motor-040 and Obsidian-9 show a similarity of 60.77%
134. Engine Clarity-7.1 and motor-060 show a similarity of 60.76%
135. Engine Obsidian-13 and PlentyChess-2.1.0 show a similarity of 60.75%
138. Engine Clarity-7.0 and motor-060 show a similarity of 60.65%
139. Engine Clarity-7.2 and Obsidian-9 show a similarity of 60.60%
140. Engine Lizard-10.4 and Obsidian-13 show a similarity of 60.60%
141. Engine Clarity-7.2 and Obsidian-10 show a similarity of 60.59%
143. Engine motor-060 and Obsidian-12 show a similarity of 60.52%
144. Engine Lizard-10.2 and motor-050 show a similarity of 60.51%
145. Engine Clover-7.1 and Obsidian-12 show a similarity of 60.47%
146. Engine Clover-7.0 and Obsidian-12 show a similarity of 60.46%
147. Engine motor-050 and PlentyChess-1.0.0 show a similarity of 60.45%
148. Engine Clarity-7.1 and PlentyChess-2.1.0 show a similarity of 60.42%
149. Engine Lizard-10.2 and Obsidian-10 show a similarity of 60.40%
150. Engine Clarity-7.0 and PlentyChess-2.1.0 show a similarity of 60.39%
151. Engine Lizard-10.2 and Obsidian-9 show a similarity of 60.39%
152. Engine Clarity-7.0 and Obsidian-11 show a similarity of 60.36%
153. Engine Clarity-7.1 and Obsidian-11 show a similarity of 60.36%
154. Engine Clarity-7.2 and Obsidian-12 show a similarity of 60.30%
155. Engine Clarity-7.2 and motor-050 show a similarity of 60.29%
156. Engine Lizard-10.5 and Obsidian-13 show a similarity of 60.22%
158. Engine Clover-7.0 and viridithas-12 show a similarity of 60.19%
160. Engine Clarity-6.0 and viridithas-10 show a similarity of 60.03%
161. Engine Clarity-7.2 and PlentyChess-2.0.0 show a similarity of 60.03%
162. Engine Clover-7.0 and viridithas-11 show a similarity of 60.02%

Meaning there is a 15-20% increase of move similarity and thus a decrease of 15-20% in originality in one year.

We asked for an explanation but satisfying answers did not came.