Definition of a chip and a chair
Literally "a token and a chair". The expression could also be translated as "it's not over until it's over". You've probably seen a similar situation at the poker table. A player loses 99% of his stack. He has one chip or the equivalent of one chip left. He ends up winning the next hand which gives him a tiny stack. The next hand, he quadruples his stack by going all in 4 way with AA. He folds a few hands and doubles up again. Thirty minutes later, he is the chip leader and 45 minutes later he has won the tournament. As long as you have a chip, anything is possible.
The expression a chip and a chair
A chip and a chair is an expression that is often used to encourage a player who has just lost a large chunk of his stack. A chip and a chair is a way of saying "keep your hopes up my good man, as long as you have at least one chip and a chair, you can still win the tournament". The expression is also used to refer to the spectacular comebacks we have seen in the past.