How do I enter a Trade when the price gaps? How do we know that the price has gapped too much?

How do I enter a Trade when the price gaps? How do we know that the price has gapped too much?

Your entry point should always be the high (for Long) or Low (for Short) of the consolidation or other pattern.  (Unless using Guy's specific methodology for entering without a breakout)

If the stock has gapped by some distance, then you do not have a trade.

If the stock has only gapped beyond your entry by a few cents, then it is at your discretion whether you want to enter the trade or wait for it to come back into the flag/pattern and look for a new entry opportunity.

Note that you can protect against gapping at a Brokerage by using a Stop/Limit order to open, where the Stop part triggers the possible trade and the Limit part controls the range of price movement in the event of a gap that you are happy to trade at.