The 8/4 6/4 Opening in Backgammon
Point-making opening rolls give you a great advantage right in the opening roll of a backgammon game. With a point-making opening roll you can secure a point early without so much as a threat from your opponent. Opening rolls that let you make home board points this early in a backgammon game help you in the long run. The 8/4 6/4 play is the only good and reasonable way to go with an opening roll of four-two.
An opening roll of three-one is the best point-making opening roll there is because it makes your five-point at the onset of a backgammon game. Playing 8/4 6/4 for the four-two opening roll may not be as good as the play for the three-one, this play still serves the same purpose as any point-making opening roll in backgammon.
By playing 8/4 6/4 in the opening roll you are making a point on your home board. By doing this you have also added a block to your opponent. By making more points on your home board you make it harder for your opponent to enter backgammon checkers. This inhibits your opponent to more conservative moves for the rest of the backgammon game.
When you do an 8/4 6/4 play in the opening roll, you are making the four-point a safe haven on the home board for your checkers. Spare backgammon checkers placed on the four-point serve as pieces you can use to hit any entering opposing backgammon checker. These spare checkers can also be used to make more points on the backgammon board.
By making the four-point in the opening roll you have set yourself up to build a formidable prime. Remember that the best primes in backgammon always include the four-point. A prime from the four-point to the nine-point and also a backgammon prime from the three-point to the eight-point would always require the four-point to be complete.
If you compare the six-one opening roll with the four-two, the four-two opening roll will still be a better option in backgammon. Though playing the six-one opening roll will instantly make a small prime at the start of a game the advantages aren't that much compared to the four-two opening roll.
Making a home board point still weighs heavier in the long run in a backgammon game. If in case you do hit your opponent's backgammon checker, having less home board points still make it easy for such a checker to enter from the bar.
Playing 8/4 6/4 for the four-two opening roll is a power backgammon play. It puts you in a situation that reaps a lot of benefits in the long run.

