White played 48.Bxh5 but according to the commentator , white's best is 48.g4

I think that 48.g4 , although more complicated is not better than the move played.What do you think?

I think you are right that the text move Bxh5 is better than g4 in dealing with the kingside pawns problem. However, in this position, I think c7 is a bit better.

c7 to draw the opposing king away from the center. Black's King has no choice but to capture White's pawn at c7. The next stage is to deal with the kingside problem, which is Bxh5. White should get a passed pawn here. The final stage is for White to capture Black's pawn at b4 and get another passed pawn. White should win this endgame.

The wrong-color-rook pawn does not matter in this case since White has two passed pawns (the h pawn and the b pawn). Let's assume that Black managed to hole up by putting his King in front of White's passed c pawn and the knight in front of White's h pawn, White can use his bishop to lose tempo and Black is caught in zugzwang. White wins.

There is a reason why g4 is not a good idea for White. It lets Black to get a counter play in this already winning position for White. After 1. g4 gxh4, 2. gxh5 h3, we have a race situation where Black is ahead. White's bishop is not in a good position to quickly guard the h1 square without losing tempo. So I believe that Bxh5 is better.

Why is 1.Bxh5 so good? Could you provide some variations after 1.Bxh5 gxh4 2.gxh4 Kxc6 3.Bg6 Kd7.

After 1.g4 is seems as if Black's best is something like 1...hxg4 2.h5 Nc3 (2...g3 3.Ke2 seems to lose) 3.h6 g3 4.Ke3 f5 5.h7 f4+ In the end, I think White keeps some winning chances. And it's exciting!

@Paul:

1. What I had in mind was 1.c7, followed by Bxh5. Not 1.Bxh5 right away.

@Chris:

You are right. I did not look at the position closely. Grabbing Black's b pawn proves to be a bigger trouble than I thought. The knight can put up quite a defense.

Here is the position after 1.c7 Kxc7 2.Bxh5 gxh4 3.gxh4

Black's best strategy is to sacrifice the knight for White's b pawn. This will result in a draw since White will have only the wrong color rook pawn. White must preserve his b pawn in order to win. This means that White King must constantly guard the d2 square making it impossible to capture Black's b pawn. This will result in a draw.

c7 followed by g4 as Chris said is better.

Nice endgame...