One thing you need to understand about options is that most professional options traders don't just put on a position. They build them. They spend weeks building their positions. They look at each of their positions as a whole position, not the individual trades that compose that position. Each trade on its own has negative expectancy, but as a combined position, it can be morphed into a positive expectancy trade. At the end of the month you should care about your position as a whole and your p&l. Let's look at an example of a trader. He is selling the ATM combo on a stock and looking to offset with the purchase of the wings 7 to 10 days down the road. His goal is to try to capture as close to a full 5 pt credit as possible. So let's say he sells the Sep ATM combo in XYZ for 3.70. Now the 42.5/47.5 wings are trading around 1.95. He is going to wait on the purchase of the wings to try to get them cheaper. Maybe he thinks volty will continue to drop and perhaps 10 days from now he can purchase the wing combo for 1.20. He now has a net credit of 2.50 in the trade. What is his risk? He has none! His risk is the difference between the 2 strikes minus the credit. So 2.50 minus 2.50 is 0! He now has a risk free trade. And his expectancy is certainly positive. If he ran a simulation on his trade going forward from that date to exp 1000 times and summed the results and divided by the number of trial runs, he would get a positive expected return. This trade certainly has a positive expectancy.
Now you might be saying that he took risk when he sold the first ATM combo. Of course he did. All option traders take risk when they are building the positions. There is no way around that. The idea is to be able to offset as much of that risk over the course of that trade as possible and create a positive expectancy trade. Neither the sale of the ATM combo nor the purchase of the wings carried a positive expectancy on their own. But combined, in this example, they turned into a risk free trade with the upside of 2 1/2 pts! Not a bad trade. All successful option traders try to build their positions towards a positive expectancy. This is why in order to be successful; you need to be a good trader. You can't just slap on a fly or a condor and sit back and watch. At some point, a trader has to trade. There is no escaping this. But the beauty of options is you can create all sorts of combinations and permutations that offset risk with each additional trade and increase your upside! That is why we trade options. Not to blindly sell juice and count our theta! It just doesn't work that way.
Every trade begins with a negative expectancy. Nothing you can do about this. However, many traders make most of their money on adjustments. In other words, when you put on trades, they are just a shell. You don't expect anything out of this shell. But somewhere down the road, you expect to have opportunities to morph this trade into something with positive expectancy. Options traders do not make binary bets. The nature of their speculation is neither so apparent nor as black and white as outright directional traders. They put their pieces on the table and play a game. They arrange their pieces in such a way so that they can make favorable moves down the road. Then they are patient and wait. By adding to your initial position 'after' the favorable move you don't change the expectancy of the trade. The expectancy 'after' the favorable move is already positive. What you change is your payoff distribution. You are making the small payoff more certain by sacrificing some of the upside potential.