First of all, Nick, I appreciate the kind words you said about me... I don't even remember posting that, but it sounds like me!
So I want to chime in, but there have been so many examples given and notes on top of that that I've decided to restart the discussion as I see it with a couple new examples (which are probably similar if not the same as other examples given, but I work better with a clean slate).
Example #1
Postflop
Andy bets 100
Betty goes all in for 50 more, a total of 150
Carl goes all in for 50 more, a total of 200
Diane calls 200
Action returns to Andy
In this example, I don't believe there is any disagreement. Andy is facing a total bet of 200 which reopens the betting to him. He can chose to FOLD, CALL (put in 100 more chips), or reraise (put in a minimum of 200 more chips).
Example #2
Postflop
Andy bets 1000
Betty goes all in for 800 more, a total of 1800
Carl goes all in for 700 more, a total of 2500
Evan calls
Action returns to Andy
So in this example, betting is obviously reopened to Andy since he is facing raises that total 1000 or more. The big question in this thread is what the minimum raise Andy can make? Is it 1000 (the original min-raise since there was no single legal raise), 1500 (the total raise Andy is facing), or 700 (the last short-raise made). Rule 47 states, "A raise must be at least equal to the largest prior bet or raise of the current betting round." According to that rule, Andy can raise 800 (the rule does not say FULL raise). The example given for Rule 47, however, does use the phrase "last legal increment". It does not specify what exactly that means... I can see it taken two different ways... 1) Betty and Carl both made legal increment raises since their short all-in is a legal action in which case Andy can raise 700 or 2) Betty and Carl's raises are not legal increments since they are not full raises. Unfortunately, Rule 48 (Reopening the Bet) does not get into HOW MUCH Andy can raise, only that he can. Since things aren't specific enough, I would fall back to the actual language of Rule 47 and say that Andy can raise 800 or more (which is the "largest prior bet or raise").
I'm going to take an aspirin.