Scoring Errors

Question
If the short stop throws a catchable ball to the first baseman to make a play on the runner, and the first baseman drops the balls, tips the ball, or doesn't stretch to make the play; which player is awarded the error?  Please explain.
Thank you

Answer
If the ball is catchable with normal effort by F3, then the error goes to F3.  If it takes more than normal effort then the error goes to F6.

If the ball hits the ground prior to reaching F3 and it is missed it is always an error on the throw.

Tom