Positional pawn sacrifices in Taichung

This weekend there was a rapid event in Taichung. In contrast with some other tournaments here in Taiwan, the ones in Taichung seem to be a tad better organized:

• The adults played in a different building from the kids. In relative silence. The usual around here in Taiwan is that everyone plays in the same hall. With a deafening noise from hundreds of unpoliced kids running around and shouting (and organizers screaming with megaphones and loudspeakers).
• The usual here in Taiwan is that a meal box is included in a tournament fee. Which is fine, unless you are a vegetarian (like me). Most other tournaments are likely to mess that up, and having a schedule so tight that there is no time to go anywhere for food. In the Taichung tournaments so far the veg lunches have been decent and I don't worry that there will be a problem getting one.
• In many other tournaments some of the pairings in the last rounds can seem odd, to the point that there are rumours and stories about fixed pairings. Never in the Taichung events I've played in.
• There are measures against cheating with handheld metal detector sweeps.
• The Taichung rating system is regularly used, fair and with transparent rules. (In contrast to the national ratings that are seldomly used and considered untrustworthy).
• Players of all nationalities are welcome to play (this is unfortunately not always the case in Taiwan).

Now to the pawn sacrifices :-)

Some time ago I read a book (skimmed rather) named "The Positional Handbook" which contains a chapter on positional pawn sacrifices. Usually the theme is that a player pushes a pawn to its untimely death just because he has better use for the square the pawn was standing on. 

Never really dared to try those in real games (only in blitz), but yesterday I did. With good results.

Black to move.

In another game I did a similar manouver that greatly helped deciding the game. In this case I did have a plan to get my pawn back.

These two are the games I am somewhat happy with. There were a few games of the other kind too...