I know its profitable because it always has been. I didn't invent this, its not a secret or obscure strategy that has to be tested, the basic principles are unchanged since the earliest days of price charts.
OK, I favour the 50EMA, many others would use the 200 or the 20 or a combination of the 9, the 15 and the 38, or the SMA not the EMA. It doesn't really matter.
Anyhow, I'm trading this strategy, and it is profitable.
Important also for a new trader is that the strategy can be learned from zero knowledge in 2 days and adequately practiced in a demo account over about 5 days. After that its the strategy that does the work, not the trader.