Najdorf 6. Bg5 game

Hi

I played this game today as black.

https://www.chess.com/a/u6uG9cgezPAW

Though i won the game, i was disappointed with tactical mistakes. In the game i made 3 mistakes.I couldn't understand why move 13 is a mistake.. More in annotations

After move 22, i was -6.xx.. and though little struggle, was able to win the match..was piece up

and 2 pawns up.

Let me know if you have any suggestions. Thanks.

Typical game between low rated players playing speed chess.  Mistakes are to be expected.

Yes,  was playing 30 mins game ..Moved to 15+10.. Will move back to 30

Can anyone explain why move 13 is a mistake? I have mentioned my thought process in annotations..

#Edited

@BharatArora23 You lost a piece...

Thanks @WorldChomp..my bad...sorry 13th move

Capturing bishop seems to be more promising. opponent rook is on g1, my LSB is
on g2, opponent DSB is on g5 and my DSB is on f6. I have two options, 1. either
capture his DSB and Rxg2 follows or 2. retreat LSB to b7. I preferred
retreating.. engine says it's a mistake. Can't understand. Please suggest on
this}

The engine probably prefers Bxg5 because it prevents white from castling. Both moves are still losing for black, but the DSB is strong on that diagonal because it keeps the king in the center.

It doesn't require calculation to figure this out. Retreating loses time (in this sharp position tempo play is very important) and although Bb7 is a good piece controlling the empty diagonal h1/a8 isn't that useful. Moreover it is better to have a bishop on g5 so White can't castle long.

The position after 16. 0-0-0 is just very bad for Black, White has developed all the pieces and castled into safety while Ra8 and Nb8 are undeveloped and the f and g files are open for White's rooks to attack the black king.

you love the Najdorf, me too, that was a good game

 Thanks a lot @Ski and @Nerwal

@theendgame3, Yes brother i like najdorf..First 10-12 moves look intuitive so picked it up..Lets see how it goes..