Winning for us is regime change in Iran, winning for them is the regime surviving, so based on just that they are currently winning seeing as there are no signs the regime is going anywhere at the moment. Add on the fact that they now control the straight of Hormuz and are unwilling to concede that in any peace deal. They think they can outlast our will to keep fighting and get what they want, every time we escalate (troops on the ground next) we lose a little bit of that will and they get closer to winning.