In 2 player, 10 card Gin, figuring out opponents cards

Question

What tactics can you use to help determine what your opponent is looking for in two player 10 card Gin?

Answer 1

In Gin, you don't get any hard information on what is in your opponent's hand until the hand is over.

This means you have to make use of whatever information you can get. The primary source of information is the discards. To be successful you need to keep track of both

• What your opponent discarded
• What you discarded

Pay attention to both suits and the number of each card. For example, if your opponent discarded the 5 of clubs, he is most likely not interested in 5's or mid range clubs.

Observe your opponent, if he usually plays fast but pauses even briefly to consider the jack of diamonds you just tossed then he most likely has several cards around that. A couple examples of what he might have.

• 10-K of diamonds
• sets of 9's and 10's but he has diamonds of both and could make another run (like 7-8-9-10 of clubs)

Perhaps from previous discards and pickups you could narrow down the options as to what he might have.

Answer 2

In Gin, you do get some hard information on what is in your opponent's hand and constantly need to add some intelligent guesses on what is probably the opponent's hand.

Hard information:

1. A pickup from the discard by the opponent - surely that opponent hold this card. Probably this card is a part of a Meld or at least a combination.
2. Your hand & discard pile - surely opponent do not hold those cards.

Softer information:

3. Opponent's discards - almost surely are not part of a meld, that is to say, opponent probably does not holds two cards in the same suit with rank {+1,+2,-1,-2} or two cards in the same rank.

4. Cards that cannot make a meld since other cards are discarded. For example, the K♠ is probably not in the opponent's hand if the Q♠ and two other Kings were discarded already.

The nice book: How to win at Gin-Rummy by Pramod Shankar suggests to keep a table of the opponent's likely hand and to mark any card that is for sure in or for sure not in the opponent's hand, for example: