OT - "Actually, you can have four outs in an inning"
I think this would make 7 in the inning, 4 in 1/2 of the inning, 3 or more in the other half of the inning. After attending my kids game the other night I can say I think it is very possible that there is no limit.
There have been 3 occurrences in the minors where a pitcher has struck out five in an inning. Kelly Wunsch did it in 1994 Scott Gardner did it in 1995 Mike Schultz did it on July of 2004
Joe Neikro of the Astros did strike out 5 in an inning in an exhibition game.