stuck at bet opportunity?

[jscobie]

How would I write the following stat; How may times a player bet the river with a highcard when he had the opportunity to do so with a highcard.

Column 1
sum(if[ holdem_hand_player_combinations.flg_r_highcard AND holdem_hand_player_statistics.flg_showdown AND holdem_hand_player_statistics.flg_r_bet, 1, 0 ])

Column 2
sum(if[holdem_hand_player_combinations.flg_r_highcard AND holdem_hand_player_statistics.flg_showdown, 1, 0])

This is how far I have got. How can I add bet opportunity to column 2?

Thanks in advance

[WhiteRider]

You can use "holdem_hand_player_detail.flg_r_open_opp", which is the opportunity to open the river.