Winning middlegame?

The following is a winning middlegame for White from Capablanca's Chess Fundamentals. It's white to play.

``````    [FEN "2nb1rk1/1pqrnppp/p2p4/2pQ1N2/6P1/1P1B1N1P/P3RP2/3R2K1 w - - 0 0"]

1. Nxe7+ Bxe7 2. Rxe7 Nxe7 3. Bxh7+ etc.
``````

I wonder about 2...g6. In this case White only wins material right?

• Why not Nxg7. Then White has a mating attack. After NxN White can also mate from the position shown. Commented Dec 9, 2019 at 18:21
• Nxg7?? Ne7xQd5 resigns. Commented Dec 9, 2019 at 21:05
• OOPsies! I can do mate in 7s pretty easy but I often leave my Queen en pris. Commented Dec 10, 2019 at 0:40

Yes, after 2...g6 black is only a bishop behind and not immediately checkmated.

But that doesn't matter much for the result -- being a full piece behind is also enough to resign. And, that he stays a piece behind is immediately obvious -- white takes a bishop, black doesn't take back. So that doesn't really need to be explained.

On the other hand, what happens after 2...Nxe7 (or 2...Rxe7 for that matter) is not as obvious, so it's pointed out.

This is related to the concept of critical moves. To decide whether some move is good, there are some things that are important to look at more deeply and some things that aren't (2...g6 doesn't need further calculation, it's obvious that white wins). In a sense the question whether the initial position is winning depends more on whether 2...Nxe7 wins than on whether 2...g6 wins, even if the position after 2...g6 isn't quite as immediately lost as after 2...Nxe7.

2...Nxe7 is a critical move in a sense 2...g6 is not.

• But if you are studying a winning position for white, you should expect black to play the best moves. Then you should consider 2...g6 rather than 2...Nxe7 since the former doesn't lead to checkmate (not inmediately at least) Commented Dec 9, 2019 at 16:02
• @MBolin Maybe at lower levels, but at higher, checkmate is not really the shortest loss... once down a piece, you are done, so forcing your opponent to also find Bh7 actually prolongs the game in a practical sense. It is either resign immediately down a piece, or force him to "prove" it a few more moves, and then resign. Commented Dec 9, 2019 at 16:09
• @MBolin: there is nothing to consider after 2...g6. Black is a piece down. Commented Dec 9, 2019 at 18:01