Let It Ride

With 3 cards — let it ride only with:
• a paying hand (pair of tens+ or trips)
• three to a royal flush
• three to a straight flush: consecutive (3-4-5 up), or one gap with a ten-or-higher, or two gaps with two tens-or-higher

With 4 cards — let it ride only with:
• a paying hand (pair of tens+ or better)
• any four to a flush
• four to an outside straight with a ten-or-higher
• four to an inside straight with four ten-or-higher cards

Otherwise pull the bet back. The trainer grades you against the exact expected value of letting each bet ride.