What is an order block, really? The definition debate

[Shadow Trader]

Everyone defines order block slightly differently, and that is why people get inconsistent results. The common version says it is the last opposite colored candle before a strong move. Others mark the whole body, others include the wicks, others use only the open to the midpoint. My view is that the exact boundary matters less than two conditions: first, the move away from it must be displacement, meaning fast, large candles that break structure. Second, the zone should be unmitigated, meaning price has not already returned and traded through it. A candle that preceded a weak drift is not an order block, it is just a candle. I mark the body plus the wick extreme only for the stop reference and use the open to midpoint as the entry area. That gives a tight, consistent definition I can backtest. Pick one definition, write it down, and never change it mid test. Changing the box after the fact is how people convince themselves their method works.

[FXS HongKong Scalper]

Displacement plus unmitigated is a much better filter than arguing over wick or body. I'd add a third: the block should have caused a break of structure on its own timeframe. Plenty of last opposite candles sit before a strong move that never broke anything, and those tend to get run through on the return. When I tested blocks on EURUSD M15 with and without that condition, the ones without it were close to random.