Hoagies and Stoagies had a debate a couple years ago between a Lutheran and a Calvinist on baptismal regeneration. Dr. John Bombaro took the Lutheran position and David Okken defended the Calvinist position.
Bombaro spent the majority of his time defending the idea that baptism is an example of performative speech that God's Word does what it says. Bombaro argued forcefully and with conviction. I think Bombaro could have done a better job answering some of the questions about not all Israel being Israel and issue of apostasy but he did an excellent job overall.
Okken's arguments all seemed very weak and he seemed unsure of his own position throughout. He often seemed to struggle because he didn't seem to really understand the Lutheran position.