The block jump is used to intercept the shuttlecock with a forehand or round-the-head forehand action.
Comparing block jumps with scissor jumps
With the scissor jump, you lead your jump with the right foot but then swap your feet positions in mid-air.
With the block jump, your feet don’t swap. You land with the same foot position as you started.
Examples of block jumps
The canonical block jump: a forehand jump-out
In this case, you jump backwards to play a forehand overhead with the shuttlecock behind your body. You start in a side-on position, jump, and remain in the side-on position when you land. The right foot stays behind the left foot during the whole jump.
Sideways block jumps
You can also jump out to the side. In this case, your body is square-on (parallel) to the net.
When jumping to the forehand side, your right foot leads; when jumping to the backhand side, your left foot leads. Your feet do not cross over; they remain wide apart throughout the jump.
When you jump out to your right, you can usually land with both feet together (and this is preferable). When you jump out to your left, however, you are playing a round-the-head forehand, and will therefore be less balanced; usually, you’ll be forced to make a one-footed landing with your left foot (but ground your right foot as soon as possible).
Block jumps into the backhand rear corner (round-the-head)
Block jumps are less effective in the backhand rearcourt, because a round-the-head movement cannot be combined with a contact point that is well behind the body.
Nevertheless, you can use a block jump if you’re able to intercept the shuttlecock while it is still level with the body (or only very slightly behind). This often requires a near-contortionist round-the-head movement!
For these round-the-head block jumps into the rearcourt, the left foot is behind the right foot during the jump (that’s the opposite way around from the forehand corner block jump).