[Buzz]

Approximately, you figure to make low by yourself roughly 30% and split low with an opponent roughly 20%.

If the pot is $128 (eight big bets) at the start of the 3rd betting round, and if it costs you $16 (one big bet) to see whether or not you'll make low on the river, and if one of the three players behind you calls, and if both of the two contributors to this betting round also contribute on the river, then you are getting about five to one implied pot odds for half the pot and about three to two implied pot odds for a quarter of the pot.

Very roughly,
50% you lose one big bet
30% you win five big bets
20% you win 1.5 big bets.

Thus:
5*.3+1.5*.2-1*0.5 =
1.5+.3-.5

If that total is positive, then you have favorable odds to see the river. If it is negative, then you should fold.

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[ QUOTE ]
Obviously if I just had a naked A2 I would have folded on the turn...

[/ QUOTE ]No.

With a bare ace-deuce, in addition to sometimes getting quartered, you sometimes get counterfeited. Instead of winning low 30% and splitting low 20%, you win low like 23% and split like 15%, something like that. (That's very crude, but close enough).

Then 5*.23+1.5*.15-1*.65 =
1.15+.22-.65

Again, if the total is positive (and it is), you have favorable odds to see the river.

So you're obviously in better shape to see the river with the counterfeit protection (A239), but even with A2K9, you still have favorable odds to see the river. In either case, you should see the river.

Buzz