Hold cards in this order, highest is listed first:-

4 Deuces

hold 4 Deuces

3 Deuces

hold a Pat Royal Flush or 3 Deuces only

2 Deuces

Any pat 4 of a Kind or higher
4 to a Royal Flush
4 to a Straight Flush with 2 consecutive singletons, 6-7 or higher
2 Deuces only

1 Deuce

Any pat 4 of a Kind or higher
4 to a Royal Flush
Full House
4 to a Straight Flush with 3 consecutive singletons, 5-7 or higher
3 of a Kind, Straight, or Flush
All other 4 to a Straight Flush
3 to a Royal Flush
3 to a Straight Flush with 2 consecutive singletons, 6-7 or higher
Deuce only

0 Deuces

4,5 to a Royal Flush
Made 3 of a Kind to Straight Flush
4 to a Straight Flush
3 to a Royal Flush
Pair
4 to a Flush
4 to an outside Straight
3 to a Straight Flush
4 to an inside Straight, except missing Deuce
2 to a Royal Flush, J,Q high

Notes:-
High cards are jack, queen, king, or ace

An outside Straight is one that can be completed at either end eg 4,5,6,7

A Straight with a missing inside card, such as the cards 4,6,7,8. Note A,2,3,4 and J,Q,K,A are equal to inside Straights