In that article, I said I would go with a modification of
@STAVKA's OBA he uses in his Leaflet House Rules if designing OBA. I stand by that. I think OBA should go away. However, if you are of the camp that OBA should always be a threat in being, I would not go with any card replacement system. I would use something similar to what
@Andrew Rogers did in Hatten: a fixed deck that never changes. All cards drawn are replaced back in the deck. This is actually a pretty clever system. The chances of placing an AR and converting to an SR are equal to (the chance of radio contact) times (the chance of drawing a black card). If you want more OBA as a designer, you can change the chance of contact or change the chance of drawing a black. The extra chit draws never get affected. The amount of OBA (on average) is the number of turns times the chance to place an AR.
Of course, the number of missions would be heavily influenced by the OBA player's ability to convert from an SR to an FFE:1. This conversion rate is influence by accuracy (which could be tweaked by the designer) and terrain.
This is a change from what I wrote in that article. There I said I would use a card replacement system if I thought OBA should remain a threat. I now would use the Hatten-style OBA system. -- jim