Get it done now. But don't think you'll be skiing hard in 4 months. That's crazy and an excellent way to get it done twice and spend 2 years waiting to ski hard again. Get it done now, and don't ski until spring. Also, if it really is torn, and you ski all season, you might have fun. A small percentage of people do completely fine without their acl's. However, what is much more likely is that sometime in the middle of the season you will form a little tear somewhere in your meniscus. After that happens, you will definitely start hurting -- hurting so bad that skiing is not fun anymore, just scary and painful. Then it will be May and you'll finally get surgery. Round about the start of the following winter, you'll try skiing again and realize that all the people who said you could recover in four months were full of shit and that eight months is much more like it. Then you'll finally ski again in January, or February. Cool, except that all the pain you felt the year before, when you were trying to ski a whole season with no acl, will be engraved in your mind. All that pain will have trained you to be really scared of being hurt, and even though your leg is healthy now, two years later, your mind will be far from it. So every time you feel pain in your leg, you will trip out and think you have to get surgery again. This fear will stay with you for the rest of the season, at least. And so you will have spent TWO shitty seasons getting over your injury: the one where you tried to ski with no acl; and the next one, where you're paranoid because of the pain you felt in the season before. If you just get surgery now, you spend one shitty season, and then you're healthy next year. So two seasons out, or one season. Which one do you think sounds like a better plan?