Say you take what Natenberg says about Strangles to be true. That a Strangle has to be a call and a put with the same expiration date. Lots start to make sense, you can talk about Calendar spreads and so on.
A call backspread, is short call and long call, right. But what do you call it when you use a put for downside price action instead of the short call. And what do you call it when you make it diagonal. Doesn't this mimic a synthetic call position?