I know most of you probably know the story behind Michael Richards' character's name change from "Kessler" to "Kramer after episode one. However, for those who came in late without a program, would anyone mind explaining it to me, please?

Thanks in advance :)

Kessler was the character's original name from the pilot, while it was still being determined if Kenny Kramer's real name could be used. (Records indicate the character was also called Hoffman at one point.) Reportedly, test audiences reacted negatively to the name Kessler, and eventually all parties approved the name Kramer. When "The Betrayal" flashes back to the first meeting between Jerry and Kramer, Jerry calls him Kessler because that is the name on the buzzer, but Kramer corrects him. Maybe Kessler is a roommate Kramer's been keeping a secret all these years (which would explain why Kramer doesn't spend more time in his own place, and why Kramer doesn't have a job but has to pay rent.)