Originally posted by Varenka25.Nb5 allows 25...Rc6 so it's hardly better.
For position 3, 25.Nb5 is even better (though Bb5 is winning too)
25.Bb5 not only guards the c6 square but it also pins the bBd7 threatening Qa8 check when the loss of both queenside pawns soon follows. This together forces 25...Rxb5 or 25...Rd5 when 25.Nb5 doesn't.
Originally posted by Varenka25.Bb5 Rd5 26.Rxe5 Rd6 27.Qa8+ Qd8 28.Bxd7+ Rxd7 29.Qxa6 Qxf6 30.Qa8+ Qd8 31.Qxa4
25.Nb5 Rc6
26.Rg8 axb5
27.Qxe5 Qc7
28.Qg5
This gives White significantly more of an advantage compared to 25.Bb5 Rd5.
25.Nb5 has the benefit of opening the d-file for White's rook.
Originally posted by tomtom232Black can do better than that against 25.Bb5...
25.Bb5 Rd5 26.Rxe5 Rd6 27.Qa8+ Qd8 28.Bxd7+ Rxd7 29.Qxa6 Qxf6 30.Qa8+ Qd8 31.Qxa4
25.Bb5 Rd5 26.Rxe5 Qxb5
White is winning. But in the following line, Black is getting killed more directly...
25.Nb5! Rc6 26.Rg8 axb5 27.Qg2! (threat of mate in 3)
Originally posted by Varenka26...Qxb5 27.Re1!
Black can do better than that against 25.Bb5...
25.Bb5 Rd5 26.Rxe5 Qxb5
White is winning. But in the following line, Black is getting killed more directly...
25.Nb5! Rc6 26.Rg8 axb5 27.Qg2! (threat of mate in 3)
27.Qg2 Rg6 and white isn't much better than after Qxe5 (though both positions are very good)
The point is that it's not better. It's roughtly the same or slightly worse but it doesn't really even matter since both moves are winning.
Originally posted by tomtom23225.Bb5 Rd5 26.Rxe5 Qxb5 27.Re1 Qb7
The point is that it's not better.
25.Nb5 Rc6 26.Rg8 axb5 27.Qg2 Rg6
The first line has an eval of about 2, and the second line has an eval of 5. And you say that it's not better?
Yes, both win, but in objective analysis it's better to find more decisive lines.
Originally posted by Varenkablack will probably play ...Rxb5 in both and ...Rc8 is maybe a better defense than ...Rc6.
25.Bb5 Rd5 26.Rxe5 Qxb5 27.Re1 Qb7
25.Nb5 Rc6 26.Rg8 axb5 27.Qg2 Rg6
The first line has an eval of about 2, and the second line has an eval of 5. And you say that it's not better?
Yes, both win, but in objective analysis it's better to find more decisive lines.
Originally posted by tomtom232Check these with a good engine and you'll see some significant refutations.
black will probably play ...Rxb5 in both and ...Rc8 is maybe a better defense than ...Rc6.
25.Nb5 Rxb5 26.Bxb5 +7 eval
25.Nb5 Rc8 26.Nd6+ +9 eval
25.Bb5 Rd5 (best, not Rxb5?) eval about +2
I know which move I prefer 🙂