Like at my day gig, we partner up with other professionals in the field to provide a Team of Experts. Alex@Stratified [maker of the Guadian Angel Overboost Protection device], or Lex on MSF has written a lengthy and detailed discussion regarding KR or knock retard. This is something I have been personally explaining to MSpeed's client's and now that Lex has summarized it into a post, I believe you guys should have a look at it. Something to note: the difference between true kncok, knock retard, and pulled timing.

LINK TO MSF: KR Explained