Worst Likely Hand
The worst likely hand is the weakest holding that you might reasonably put another player on. You use it to see how bad your opponent's hand could be.
The simple explanation
When you try to read an opponent, you think about the best and the worst hands he might have. The worst likely hand is the lowest in that group.
A closer look
The idea helps with decisions. If the worst likely hand that your opponent has is still better than your hand, you should fold. If his worst likely hand is weaker than yours, you may have a call or a raise. It is a way of narrowing a range. The estimate must be realistic, since a very small chance of a bluff does not matter much.
A practical example
A tight player raises, and you put him on at least a pair of tens. That is his worst likely hand.
Full explanation
The worst likely hand is the weakest holding that you might reasonably put another player on. You use it to see how bad your opponent’s hand could be.
The worst likely hand is the weakest hand an opponent might have.
You use it to read the opponent.
It narrows his range.
Be realistic about it.