Sorry - I don't know why you never got a reply to this.
To do this we need a new column to count the number of times the player won at showdown when they check/raised the turn, and one for the number of times they saw the showdown.
cnt_t_check_raise is defined as:
sum(if[cash_hand_player_statistics.flg_t_check_raise, 1, 0])
The new column we need is:
cnt_t_check_raise_wsd =
sum(if[cash_hand_player_statistics.flg_t_check_raise
AND cash_hand_player_statistics.flg_won_hand AND cash_hand_player_statistics.flg_showdown, 1, 0])
Then:
cnt_t_check_raise_sd =
sum(if[cash_hand_player_statistics.flg_t_check_raise AND cash_hand_player_statistics.flg_showdown, 1, 0])
The stat expression is then:
(cnt_t_check_raise_wsd / cnt_t_check_raise_sd) * 100
You can do the same for the river, replacing the _t_ with _r_.
Both stats are attached.