Kasparov said human+computer beats just computer. What does human bring to the table in such teams? Its seems to me nowadays computers simply play better, i.e. they consistently choose better moves. Where does human factor come into play, how can a human help engine to beat another engine?

Or was Kasparov simply wrong?

Edit: here's the podcast, most of it is politics, chess part is near the very end
https://www.samharris.org/podcast/item/the-putin-question
Experienced human correspondence chess players with a strong chess engine definitely play better chess than just the engine itself.

If you think about it, the human player could always simply follow the engine moves without any thinking.  However, you're not going to win the world correspondence title if you don't do your own analysis. You have an engine, but your opponent also have an engine! You just can't win a game unless you guide the engine.

A strong International Correspondence Chess Grandmaster know how to analyze a chess position with a chess engine. They can make a move on a board, and evaluate the new positions again with the engine. There is no way the engine by itself can beat this human+engine perfect combination - tactics + long-term strategic thinking.


Human can make some moves on the board, that simplifies the search process (searching at depth x is not equivalent to x+1)
Human understands drawn endgames. They can guide the engine not to choose a line that wins a pawn but draw 50 moves later in a rook ending
Human can try the engine lines, play some training games, test the new positions etc. Chess engines can't do that by itself!