your mid-point while your opponent still holds either your 4pt, 5pt or bar point.
In the above position, the strategies are clear. Black tries to bring all his checkers into his home board without leaving a shot. If he has to leave a shot it will normally be on his mid-point after White has vacated his own mid-point. White will, therefore, have only an indirect shot (requiring a combination of both dice) to hit. Ideally, Black would like to throw a set of doubles and clear his mid-point without leaving a shot. White has three aims: keep the high anchor, keep the mid-point as long as possible and build a strong home board.
Doubling strategy is straightforward. Black can double when he has the equivalent of a racing double (based on pip count alone). What is slightly surprising is that White can take with a deficit up to 50 pips. As his chances of winning the race decrease, so his chances of winning by hitting increase. In the variations where his hitting chances are high, it is imperative that he has a good home board, otherwise what would be a take becomes a drop. In the position above, the pip count is Black 99 White 110, so the correct cube action is for Black to double and White to take.