Squash boast types

Skid boast is a shot that is played from the back corners. The idea is to hit high on the sidewall , very close to the front wall intersection. It is best to hit this off a deep rail shot. The ball will hit the front wall high and lob itself into the opposite back corner. If hit correctly, huge amount of spin will be imparted to the ball.

If Start quadrant = Back-right, End quadrant = Back-left
If Start quadrant = Back-left, End quadrant = Back-right

Trickle boast is a boast that is hit from the front corners. The ball hits side wall and just above the tin and generally lands in the same quadrant of the court (generally most boasts will end up in a different quadrant of the court from where it is played from). This is used for deception where you shape up for a drive and then play a tickle boast.

If Start quadrant = Front-right, End quadrant = Front-right
If Start quadrant = Front-left, End quadrant = Front-left

Corkscrew is a shot which is played from the front corner. The ball hits side wall high and the ball ends up in the back corner. I have rarely seen this played (maybe the only time was when I saw Mark Talbott play a friendly with a local pro).

If Start quadrant = Front-right, End quadrant = Back-left
If Start quadrant = Front-left, End quadrant = Back-right

Reverse boast or reverse angle is a boast where the opposite sidewall is hit first. i.e. a forehand reverse boast for a right-hander will hit the left sidewall first. This is a common(overused ?) shot by some people at C, B level. It can be easy to read and in such a case sets up for any easy winner for the opponent.

And yes - a boast can hit just two walls. Such a boast is called a Working boast. This is an attacking shot intended to move your opponent ... the three wall boast is a defensive shot (unless you get a lucky nick) A variation on the three wall boast is the sidewall-sidewall-frontwall shot. I don't know what this is called.

Also you have a Volley boast which is self-explanatory.

Backwall boast is hit directly off the backwall also known as the desperation shot. It is played when one has no other way to get to the ball to the front corner. The ideal way to hit it is to wait for the ball to get as close to the backwall as possible. Then aim for the top of the backwall . This gives the ball a lot of height and spin. When it hits the front wall it will shoot straight down. Ideally it should land tight to the sidewall. This shot is great to practice against lower skilled opponents. Once you perfect it the shot can actually turn into a good defensive shot.

Side-side-front is called a double boast , not hit intentionally in softball.