Diamond and 1
In a diamond and 1, the bottom player can cover the corners as in a 1-3-1, or keep him inside and cover the corners with the wings. Both versions are shown.
Defender 3 guards opposing match-up O2 man-to-man, denying passes. The point of the diamond always points to the ball, helps defend penetration if O2 gets the ball, and double-teams O2 in scoring range.
If the match-up uses an off-ball screen, defender 3 trails the cutter, and a diamond player extends the screen and bumps the cutter (the diamond can help on a curl but not a fade).
Trap if the match-up uses a ballscreen (or optionally shock).
See Defence - Triangle and 2.
1) Extended 1-3-1 slides
Slides of the diamond are based on an extended 1-3-1, taking out point defender 3.
X5 covers slot-to-slot along the 3-point line, X2 and X4 cover the wings (take first pass, or switch with X5 on a dribble entry), X1 runs the baseline.
See Defences - Extended 1-3-1 basics.
X2 takes the ball on the wing (and stays with the ball if 3 dribbles to the corner, and back out), partner X4 has weakside, X5 has high post, X1 has low post.
X4 takes a skip pass, X2 covers weakside, X5 has high post, X1 has low post.
X1 takes a pass to the corner, X5 covers low post, X4 has high post (not a soft trap or trap).
X4 would bump X1 back if 1 dribbles out of the corner.
2) Keep X5 inside
X5 stays inside, between the ball and the basket (does not run the baseline), X1-X2-X4 cover the perimeter.
X1 takes the ball above the foul-line extended, X2 and X4 cover the wings down to the corners.
Try to force the ball away from the match-up.
This diamond and 1 can also be used to double-team a dominant post player, optionally with X4 denying and X3 in the diamond. With the ball out top, X1 could sag to help on the high post.
X2 takes the ball on the wing, partner X4 has weakside, X1 has high post, X5 has low post.
X2 would follow a pass (or dribble) to the corner, and force baseline.
X4 covers a skip pass (X1 could bump him), X2 covers weakside, X1 has high post, X5 has low post.
X4 follows a pass to the corner.