This is something I would like to backtest. It is a simple strategy for which I want to see is profitable over a broad range of instruments. I heard it on a podcast last year with a trend following trader.

Basically the buy signal is to enter if the price rises 20% from a low point, and to sell when the price falls 20% from the first highpoint after entering the trade. The goal is to capture the middle meat of a trend.

The problem I have is in coding the strategy. I have read through the tutorials and very little of the coding has made sense to me at this stage.

The first step is describing the strategy in words, as precise as possible.

For instance, "rises 20% from a low point" is ambiguous. 20% of what? Once you got a precise description, the coding step is easy.

I think he means (p2-p1)/p1×100 = 20

That would be easy to code, only problem is that it would hardly ever enter a trade, so he probably meant something else.