This is very true. From the project page https://github.com/billforsternz/retro-sargon
"However there's no doubt that in general the horizon effect, as it is called, is a massive limitation on the strength of an engine that does a full width, fixed depth search with no pruning. Sargon runs well enough. It plays ugly anti-positional chess, but it does try to mobilise it's pieces and it's pretty decent at tactics and will sometimes tear you apart in a complex middlegame if you don't pay attention. But then it might not be able to finish you off. Despite being able to search deeper [in endgames] it still doesn't understand endgames because promoting pawns takes so many ply. And even winning with say K+Q v K is beyond its horizon unless the opponent's king is already corralled with Sargon's king nearby. I am tempted to add a simple "king in a decreasing sized box" type heuristic to the scoring function to fix that - but that's not really software archaeology is it? A similar problem, probably fixable in the same way is that Sargon will sometimes drift and concede a draw by repeating moves even in an overwhelming position. This is a reflection of Sargon's scoring function, which doesn't have any positional knowledge. Sargon just tries to win material, and if that's not possible control more squares than the opponent. This was typical of the era, in the early days of chess programming the pioneers were delighted to find that minimax plus alpha beta and a simple material plus board control scoring function was sufficient to play at least reasonable chess. But it was only a starting point for real progress."
This is a little misleading because I didn't parse the depth parameter of the Go command when I implemented Tarrasch Toy 10 years ago. I know this because I adapted the UCI protocol handler from then to the new Sargon 1978 engine project, and this time my Arena testing showed the value of that parameter, so I implemented it for Sargon. So in your game Sargon will always use depth 6, and Tarrasch Toy 0.905 will just make a (bad) judgement call about what depth to go to. If you play a match with no depth specified and 15/20/25 minutes each plus increment as I did, you'll find Sargon 1978 outmatched. This is not surprising because (by coincidence only) Tarrasch Toy uses more or less exactly the same approach as Sargon 1978 (shallow, full width search plus SOMA), but Tarrasch Toy has a more elaborate scoring function, with quite a lot of chess heuristics (versus Sargon with nothing but material and board control). Tarrasch Toy uses C++ not assembly, but has fast lookup table based move generation (Sargon couldn't afford such luxuries) to compensate. Tarrasch Toy 0.906 is significantly stronger than Tarrasch Toy 0.905, mainly because of better time management, 0.906 at Elo 1492 is much stronger than Sargon 1978, 0.905 is still significantly stronger but my expertise at measuring these things precisely is non-existent unfortunately.
At depth 6 it crushed Tarrasch Toy. Appeared to be more tactically alert.
