Some people were asking how the cutter is thrown or gripped. This is the way I do it and it's been successful for me.
It's pretty hard over the internet to show good grips so this is the ball with the big horseshoe.
This is the way that I believe Mariano Rivera throws his cutter. This is a way to do it and this works for me also. Correct me if I'm wrong.
This is the way I throw my cutter. If you want to throw this pitch and you work on the first way I'm not sure if it's better than this way. I throw it this way but I'm used to it and this is how I like to throw it. I'd expirement with both grips to see which you like best.
Again here is the picture of the close seams.
And this is a picture of my grip when I throw my cutter.