Lichess puzzle 87510: How much calculation would a strong player do before playing Bg4+ when white has a range of (all losing) responses? Lichess puzzle 87510 has this position.
[FEN &quot;r1b1k3/pp4R1/2q3RQ/4p3/5P2/bP2P3/2P1K2P/8 b - - 0 1&quot;]

The solution is 1...Bg4+,.after which White has 6 legal moves:

1...Bg4+ 2. Rxg4 Qxh6, which is the computer solution, possibly followed by 3. Rg8+ Bf8,


Kd3, which is mate in 7,




Kd2, which is mate in 8,




Ke1, which is mate in 5,




Kf1, which is mate in 4, and




Kf2, which is mate in 4.



I feel like a human player in a tournament would not calculate the whole decision tree, and probably just intuit that 1...Bg4+ is going to win since black can continue with a range of powerful moves Qf3, Qc2, Rd8, and Bb4 and at least one of them is with check, depending onWhite's response.
Question: How much calculation would a strong player (say an FM+) perform before playing 1...Bg4+?
It's a dangerous movem Black begins with an exposed king, with mate threats and a possible rook skewer, and queen attacked, and Black responds by creating an undefended bishop.  If the checks ended, Back would probably lose.
I'm an FM, and my calculation process would be as follows:

1) See that after 2.Rxg4 Qxh6 2.Rg8 Bf8, I'm clearly winning and White has no follow up.

2) Look at White's king moves to get out of check. Immediately Kd1, Kd2, Kd3 can be discarded since they just let me play ...Rd8+ for free. Also, Kf1/Kf2 lead to the same thing after I play 2...Qf3+. So I'd just look at Ke1 and Kf2.

3) Everything looks good, so I'm done.

If I were in time trouble, I'd play 1...Bg4+ seconds after seeing it. Since 2.Rxg4 doesn't work, there's no practical risk to playing it.