Determining the strength of your hand relative to your opponent's range involves analyzing the board texture, your opponent's actions, and their likely range of hands. You need to consider how well your hand fits the board, how your opponent has reacted to the flop, turn, and river, and what types of hands they are likely to be playing in that situation. By combining these factors, you can estimate the likelihood that your hand is the best and make informed decisions about whether to bet, check, or fold.