William Tyndale, the father of our English Bible, has been referred to as the "primary" or "principal" translator of the KJV by a couple KJV-only authors because such as large percentage of the KJV is said to come from Tyndale.
In his preface to his 1534 New Testament, William Tyndale wrote: "I had taken in hand to look over the New Testament again and to compare it with the Greek, and to mend whatsoever I could find amiss." Tyndale clearly regarded the Greek New Testament as superior to his translation and as the standard for revising or correcting it. Tyndale thought that it was good to correct and attempt to improve an English translation, using the standard of the Scriptures in the original languages.