In yesterday's session, another tactical consideration emerged - the use of Chicago cards as response actions. Two combinations came up in yesterday's game. First, we realized that the negative effects of a "Reverse Counting" card can be mitigated by playing "No Fifteens" when one's own hand would otherwise score heavily in fifteen-point combinations. Now the order of play is important. We'd already realized that a "Reverse Counting" is most effective when played on the dealer, who will count negative for both his hand and the crib. But since the dealer's opportunity to play a Chicago card comes after his opponent's, he has the opportunity to respond with a "No Fifteens."
Second, we'd already recognized that an advantageous situation in which to play "No Fifteens" is when one holds a hand that scores well but has no fifteens. So a logical response by the dealer to "No Fifteens" is to play "Trade Hands," so as to take advantage of the opponent's well-prepared hand and otherwise-well-played "No Fifteens."
Now that these counter-moves are evident, they become considerations for the non-dealer as to whether to play a Chicago card for which the dealer still holds the counter-card. Similarly, that means that the counter-cards might be held in reserve rather than played aggressively.
I'm finding that this conceptually simple variant on classic cribbage has layers of depth that I hadn't originally appreciated.