IBB logic

Does anybody fully understand the logic HAL uses for intentional walks?

On my 80's team I was facing Jim Clancy (R) in the 4th inning with 2 outs and a man on 2nd. Clancy issued IBB to Glen Braggs(R), to face Nettles(L). Then a wild pitch moved the runners, so Clancy issued a IBB to Nettles to face Oquendo(S).

I know what Braggs card and Oquendo is, but don't know anything about Nettles. Hoping understanding the logic will give me some insight on Craig's card.

I have gotten a couple responses already, but nothing very definitive. So hoping for more input.

Thanks,

John

It might have to do with Clancy, Nettles, or Oquendo.