[isatrader]

I'm wondering whether, if are looking at breakouts in the strongest sectors / groups etc, the Mansfield RS tends to be positive anyway? 

Mostly in the strongest groups, but it's an important quality factor, as if the RS line is just moving above a still declining zero line (52 week RS MA), then it has much higher risk of failure than if the zero line (52 week RS MA) has already flattened out and is turning up, with the RS line making new highs ahead of the price action. So, it is a important factor in determining the quality of the breakout, and can help with opportunity cost considerations, especially when comparing multiple stocks from the same group in order to decide which one to trade.