Opening theory versus strong AI suggestions I have realised that Opening theory usually contains the highest quality chess, they have been pruned and honed. However sometimes when I am going through an opening with say Stockfish, I find that at times Stockfish has different recommendations than the opening has.  So I have been wondering how does the quality of play in an opening compare with the abilities of a 3300 elo chess program?
There are at least four possibilities, all of which are pretty normal.

One, the opening theory is from a good, recent book. The author will have used the strongest engines himself, and also applied his own chess knowledge, and spent enough time to find better moves than the engine did.

Two, the author did see the computer move, but thought it was not practical for a human to play like that, and that his move was almost as good but much easier to understand, explain and play.

Three, the position is drawn (as most opening theory positions are) and in the final analysis both moves will turn out to be good enough.

Four, you've found a mistake in the book.

All of those happen all the time.

If you have a concrete example, you'll get much more concrete responses.