Finding the best category of poker hand
I think that it would be best if you could put those constants into a enum so that you can use Enum.values to get them all in an array. If so you can do this:

enum Play {
 TWOS, THREES, FOURS, FIVES, SIXES, SEVENS, EIGHTS, THREE_OF_A_KIND, 
 FOUR_OF_A_KIND, FULL_HOUSE, SMALL_STRAIGHT, LARGE_STRAIGHT, ALL_DIFFERENT,
 CHANCE, ALL_SAME; 
}

class Main {

  int playGame(Play play) { 
     // you need to implement this method returning something meaningful.
     return 0; 
  }

  int best() {
     return Stream.of(Play.values())
                  .mapToInt(this::playGame)
                  .max().getAsInt();
  }
}


If you want to keep those constants as independent static final (Strings?) then you will need to create a list of them explicitly:

//...
static final String TWOS = "TWOS";
static final String THREES = "THREES";
//...
static final List&lt;String&gt; PLAYS = Arrays.asList(TWOS, THREES, ...);
//...
int best() {
   return PLAYS.stream()
               .mapToInt(this::playGame)
               .max().getAsInt();
}