I realize that probably sounds crazy, but when I looked at the other side of the equation and compared engines where the Ponder Hits are most different, it further re-enforced the idea. I don't think it's a coincidence that the engines which are most contrarian, are also some of the most beloved engines within the computer chess community. Zappa II Mexico's name is all over the Most Different Ponder Hit list. Other engines widely considered "special" also appear regularly on the Most Different lists -- Komodo, Stockfish etc.
As I thought about this, I realized that I had sensed these stats intuitively even if I had never actually put them into words or consciously considered why I like some engines more than others. I recently tested Critter 0.70 and I knew early on that I was seeing something special. The results were impressive but it was much more than numbers in a crosstable that impressed me. It was the way it achieved those results -- by being different; by performing with élan.
Obviously, those attributes are subjective and difficult to quantify but it's something I suspect we all know intuitively when we see it. I think that's why I've never really cared for any of the clones, regardless of how well they performed in engine testing. They have no personality. They do well by doing less and doing it faster than other engines. Not because they have anything interesting to say or anything new to add. They're derivative in a purely negative way, which, in my eyes, somehow makes them less compelling as characters and far less interesting as chess players.
Thinking out loud,
Musashi
Code: Select all
Ponder hit: Most similar pairs (different families only)
# Pair %
1 Fritz 12 – Naum 4 32-bit 67.3
2 Fritz 12 – Critter 0.60 32-bit 65.3
3 Fritz 12 – Onno 1.1.1 32-bit 65.3
4 Fritz 12 – Doch 09.980 32-bit 64.9
5 Fritz 12 – Rybka 4 32-bit 64.7
6 Fritz 12 – Grapefruit 1.0 32-bit 64.1
7 Fritz 12 – Protector 1.3.4 32-bit 63.6
8 Bright 0.5c – Critter 0.60 32-bit 63.4
9 Fritz 12 – Naum 4.2 64-bit 63.3
10 Naum 4.2 64-bit – Fritz 12 63.3
Ponder hit: Most different pairs (different families only)
1 Rybka 3 64-bit – Deep Shredder 11 64-bit 49.3
2 Rybka 3 64-bit – Grapefruit 1.0 32-bit 50.1
3 Zappa Mexico II 64-bit – Toga II 1.4.1SE 53.2
4 Zappa Mexico II 64-bit – Naum 3 64-bit 53.2
5 Zappa Mexico II 64-bit – Ktulu 9 53.3
6 Zappa Mexico II 64-bit – Spark 0.3 64-bit 53.4
7 Zappa Mexico II 64-bit – SmarThink 1.10 32-bit 53.7
8 Zappa Mexico II 64-bit – Onno 1.0 64-bit 53.8
9 Rybka 3 64-bit – Toga II 1.4.1SE6 53.9
10 Critter 0.70 32-bit – Fritz 12 54.0