Association Rules Openings:
With the exception of a few advanced players and those with a death wish, the decision to play first in an Association Rules game is one of tempered realism. They don't believe the opponent can hit. For that matter, they don't think they will hit in on third turn either, which is why they run from the baulk line. The goal of the player who plays first is usually to control the game on the fifth turn. The most common first shot is to the maximum distance (or slightly south/west of it) on the east boundary. Fifth turn is special because the player is not required to start from the baulk line, and they are the first to have the freedom to play either of their balls. Their wager, so far, is that they could take advantage of this turn and start the game in control. Alternatively, the opposition is hoping against hope.
The second ball in an association rules game can play it conservative. If they feel the opposition cannot make a good offensive play or a nice leave, they can play to a defensive position to make all fifth turns more difficult. On the other hand, the second ball may play to an enticing position that leaves a risky shot for the third ball and the possibility of a seemingly short shot on fourth turn. In this case, the player is optimistic. “The opponent may miss, but I will not,” is the mantra. Most openings follow these philosophies. It is the games where neither player gets a break going that interest me.
When the situation leaves striker with an easy roquet, but no odds on opportunity for offense, the tactical possibilities are endless. When American players complain about the lack of strategy in the association game, it becomes annoyingly clear that they have never tried to play a canny turn in which they must position all four balls in beneficial positions without making a hoop. Those five to seven shots can yield incredibly shrewd positions if the striker has a clever sense of sadistic humour.
The basic priorities of an association leave are: 1) make hoops, 2) separate the opponents while giving the striker or partner an easy play, and 3) make the opponent's play as difficult as possible. If there is a better than 75% chance to make a hoop, take it. Otherwise, change to the second priority of separating the opponents.
There are many beneficial positions one can occupy while fulfilling the simple task of separating the opponents. The striker may join near the boundary (with a rush is better) while leaving the opponents more than 4 yards on court. Positioning the opponents in useful positions like your hoops or pioneer hoops is preferable. One of the best leaves involves cross-wiring the opponent balls at the hoop you wish to make. This leaves them blocked from hitting each other while quite close in proximity to your hoop. Whichever ball the adversary plays, they will leave one of their balls at that very hoop (that is, unless they hit in). This leave is nearly impossible for beginner players as it requires incredible luck or skill to end your turn with the opponents in such a precarious position. A much more likely, and thus useful, leave is to finish the turn joined with your partner ball near either one of your hoops while leaving the opponents on court (hopefully at useful pioneer hoops). If this is a corner hoop, you can leave a trap discouraging any shots at your balls while leaving a possible break. At the very worst, with both opponent balls separated, the next turn should yield at least one point scored before you must focus on separating the opponents once more.
Every so often, you are left with a difficult shot to start the turn. If you are not confident that you will have more than one shot this turn (let us say, under 50%) it is important to put yourself in the opponent's shoes. Which ball, if left in its current position, is most helpful to the adversary. The best play may be to take that ball away. Next, consider your easiest shot. This shot could maximize your chances of taking control. Last, but not to be forgotten, is the risk of missing these shots. Which of these misses will cost us the most and truly aid the opposition.
I apologize for not going into specifics, but these general guidelines apply to the multi-faceted scenarios that arise in the midst of a match. Hopefully any one of these lessons can help on multiple occasions during your journey into the madness that is competitive croquet.