"90% win rate" is the headline every signal group leads with, because it sounds unbeatable. It isn't. Win rate on its own tells you nothing about whether a strategy makes money, and it's easy to fake a high one while quietly losing.
How a 90% win rate loses money
Imagine a strategy that risks 100 to make 10, and wins 9 times out of 10. Nine wins earn 90. The one loss costs 100. Net result: down 10, despite a 90% win rate. Any strategy with a huge stop and a tiny target can manufacture a win rate that looks amazing and bleeds an account dry.
What expectancy measures
Expectancy is the average result of a trade, measured in R, your risk unit. If you risk 1R per trade, a strategy that wins 40% of the time at 2R and loses 60% at 1R has an expectancy of (0.4 × 2) − (0.6 × 1) = +0.2R per trade. Positive expectancy means the maths is working for you over many trades, regardless of how often you're individually right.
Why this changes how you read signals
A 40% win rate at 1:2 risk-reward beats a 90% win rate at 1:0.1. That's why LazyChart fixes every signal at a 1:2 ratio and reports history as expectancy in R, not as a marketing win-rate. You want to know what an average trade returns, not how often the tool gets to feel right.
None of this guarantees profit, markets change and past results don't repeat. But it means you're judging a strategy by the number that matters. Informational and educational only.