If you are ahead in the Upper Section, then you can afford to continue being aggressive in the middle game. For example, if you the Fours, Fives, and Sixes filled and you are six points ahead toward the Upper Section bonus. You can play more opportunistically to try to make the Lower Section combinations, knowing that even if you fail, you can afford to fill in the less than perfect tallies for the remaining upper categories and still have an excellent chance of making 63 points and earning the 35 point bonus.
Assuming the conditions above, consider a roll of 1-1-2-2-6 with your Full House unfilled. Early in the game you would have kept the pair of 2’s, in keeping with the rule of holding the higher pair. However, now it is better to keep the 1-1-2-2 because even if you don’t succeed in making the Full House, you can fill in the Aces entry without falling behind in the quest for the Upper Section bonus. In the same manner, you can sometimes try for a hand that you know will be difficult to make such as the 4 of a kind or the Large Straight, knowing that you can record the score in the Aces or Twos categories as a fallback.
Though you are playing more aggressively, it is important to never fall behind the pace to secure the Upper Section bonus. Therefore, you must maintain vigilance while being opportunistic at the same time. For example, assume you are ahead by 4 points you can be more aggressive with the Aces and Twos unfilled then with the Fours and Fives unfilled.
When you are on par in the Upper Section and you are set to make the bonus, it is best to play similar to the opening game with some strategic differences. First, it is necessary to consider what you have already filled. You will have to proceed a little more cautiously so as not to put the upper bonus at risk. As the game proceeds, falling behind in the Upper Section becomes more and more problematic, as opportunities to make up the shortfall begin to diminish. As such, when on par, continuing to record an average of three of each value in the Upper Section should be your main concern.
Remember that earlier in the game, with a Full House or a Small Straight plus a pair, preferential treatment was given to high values of dice. When in the middle game, and only on par for the upper bonus, preferential treatment should be given to any pair that corresponds to an unfilled upper category. As such, even lower pairs of Aces or Twos, if not already filled, should now be kept in the hopes of achieving three or more of that value.
As in the case of being ahead, if the opportunity presents itself to make a 4 of a kind of Fives or Sixes when the corresponding upper category is already filled, it is generally correct to take the risk to do this. This is especially true if Chance is still unfilled and can be used.