Goiko, in my experience, does not throw a good cortada. He probably throws it the hardest, but when the shot takes its second bounce at the 11-line, I don't consider that a good kill. A lot of backcourters do this too, and I think it's the least effective shot with the greatest chance of going out of play (pad) in jai-alai.
Michelena told me that a good cortada is thrown softly, crosses the side wall, and dies before the 7-line.
I've seen Arietio throw it well, Rekalde too.
At Dania, it's still Arriaga, and Diego in 2nd.
On defense, and this goes for all kill shots: JABI!