A bouncer is another fearsome side-arm in a well-equiped fast-bowler's array of weaponry. The slowest this can be bowled is about 80 mph, below which it turns into an appealing prospect for immediate dispatch over the pavilion. This, from the bowler's p.o.v., is undesirable.
To bowl one of these, just pitch the ball between 11 and 16 yards down the crease. Ideally, the ball should fly up in the batsman's face, in a shit-scary way. Due to the fact the fast bowlers at the top of their jump, arm raised, often make about ten feet from ball to ground, angle of incidence is not an issue. In the 1990s, Allan Donald and Curtly Ambrose practically wrote the best practice manual on this. The bouncer is now such standard currency that regulating laws have been introduced. Only two bouncers an over may now be bowled, at the interpretation of the umpire. If you're bowling bodyline, a bouncer will be especially intimidating, if hard projectiles at the face at 90 mph sounds a bit tame for you.