On third street you hold two down cards and one up card. What you are looking for is three low cards.
Hand Classes:
• Premium: three cards to a wheel, such as A-2-4
• Strong: any three cards 6 or lower
• Playable: three cards 8 or lower
• Fold: anything containing a card 9 or higher, or a pair
The Simple Rule:
Three cards to an eight or better is worth continuing with. Everything else is usually a fold, especially against an opponent showing a low card.