Oh-it's felt inference, not felt interference. Hasty reading? Can be a killer, I know.

The latter is where the passer rubs the ball with a felt cloth to increase its load of electrons making the ball more adhesively adhere to the receiver's positively charged velcro gloves. Big no no. Bill Belilchek or somebody worked that out once.

The former is something you do with an implication in the quiet privacy of your mind to bring it to life. Most of the time, one works on the implication with keen intellectual effort; other times, the inference just emerges from some darker corner of the mind all on its own.