My summary:
1) The OBR and FED rules on "deflections" out of play are different, although they will result in the same decisions much of the time.
2) ASA is also different (apparently, at least -- based on greymule's play).
3) Greymule first answered "one base", then "two", then "one" again. IF he'd only answer "three" and "four" he could be sure to be right.
4) I agree with Carl -- two bases.