3.9: Continuity and Read-Based Systems

Chapter 3: Offense

Offenses that do not end: Princeton, Flex and dribble drive motion, each a whole system rather than an action, and what distinguishes a continuity from a set play.

New terms introduced (4): Dribble drive motion, Flex offense, Princeton offense, Triangle offense. Diagrams: 4.

A set play ends. It gets the shot it was designed for, or it does not, and either way the possession has to start again with fewer seconds on the clock. A continuity does not end: it returns to its own starting shape, so the same sequence can be run again immediately, and again, until the defense makes a mistake or the shot clock runs out. A read-based system is looser still: it has no sequence at all, only rules that say what each player does in response to what the ball and the defense do.

The three systems in this lecture are whole offenses rather than actions, which is why each gets one card covering the system and not one per beat. Section 1 is the Princeton offense, read-based, built on the high post and the back cut. Section 2 is Flex, the clearest continuity in the sport. Section 3 is dribble drive motion, a spread system with no post player at all. Section 4 is what they have in common and what makes a team choose one. Section 5 is the triangle offense, a system built on a triangle of three players on one side of the floor.

1 Princeton

The Princeton offense is built on two things: a big who can pass from the high post, and five players who will cut to the rim the instant they are denied. The ball goes to the high post; the passer is then either open to cut off him, or is being denied, in which case he back cuts and the high post drops the ball to him at the rim, as in Figure 1. There is no called sequence. Every option is a rule about what the defense has just done, which is why the offense can be run at any speed and why a team that is patient with it gets a layup out of a possession that looked like nothing.

A 5-out floor with the big, 5, at the high post, labeled high post. 1 has the ball above the right elbow, outside the arc; 2 is at the right wing, 3 at the left wing and 4 in the left corner, each with his defender, and the right corner is empty. A dashed pass goes from 1 to 5. 1's defender, x1, has stepped to his left, onto the high side of the passing lane from 5 back to him, labeled denied. 1 back cuts behind him, straight down the other side to the rim, labeled back cut, and a dashed pass from 5 drops toward the end of that cut; x5 is in the lane below 5. From the end of the back cut, a second arrow takes 1 out along the baseline to the empty right corner, labeled clears. 2 cuts from the right wing across toward 5 at the high post, labeled handoff.
Figure 1: Princeton. The ball goes to the big at the high post. The passer’s defender denies the return, so the passer back cuts to the rim and the high post drops it to him. If the cut is covered, the passer clears and the next guard comes off the same big.
Setup
Five players spaced outside the arc, or four out with one at the high post. The big at the free-throw line or an elbow, facing the ball. Everyone within one pass of the ball.
Trigger
The entry pass to the high post.
Read
The passer reads his own defender: denied, back cut; not denied, cut off the big’s shoulder for a handoff. The high post reads in order: the back cutter, the shooter whose defender helped on the cut, then his own shot or drive against a defender who has to stay home for both. Anyone whose cut is covered clears to a spot and the next player runs the same read.
Payoff
A layup off a back cut, or an open shot from a defense that stopped denying to prevent the back cut.
Beaten by
Refusing to deny: the defenders play a step off, concede the catch on the perimeter and take away the cuts, which makes the offense shoot over a set defense. That is the pack line idea of lecture 4.3 applied to a cutting team.
Action 1: Princeton: the high post passes, and every denial becomes a back cut.

2 Flex

Flex is a continuity, and the clearest one to learn because its unit is two screens. A player cuts across the lane off a cross screen at the block, which is the flex cut; the man who set that cross screen then receives a pin-down from the top and comes up to the slot, which is the screen-the-screener half. When that is finished, the floor is back in the shape it started in, mirrored, and the same two screens can be run again on the other side, as in Figure 2 and Figure 3.

The ball is with a guard at the left slot, and a second guard stands at the right slot. A big stands on the right block with a screen bar at his right side, between him and the defender of a player out on the right side of the lane near the baseline; that defender is on the baseline side of his man. The player cuts across the lane just over the top of the big and the screen bar to the left block, labeled flex cut, and the label cross screen sits just below the big and the screen bar. A dashed pass arrow runs from the guard at the left slot down to the end of the flex cut, just above the left block. The guard at the right slot cuts down into the lane toward the big. The fifth attacker stands in the left corner. Every attacker has a defender.
Figure 2: Flex, first frame. The cutter comes across the lane off the cross screen at the block, looking for the pass on the flex cut.
The ball is with a guard at the left slot. A player stands at the left block and another in the left corner. A third player stands in the lane above the right block with a screen bar under him, labeled down screen, set on the defender of the big at the right block. The big cuts up past the screener's outside shoulder to the right slot, and a dashed pass arrow runs across the top from the left slot to meet him there. A second cut arrow runs from the screener down to the right corner, crossing the big's path. The label and it starts again sits in the top right corner of the court. Every attacker has a defender.
Figure 3: Flex, second frame. The man who set the cross screen comes up off a down screen to the slot. The floor is now back in its starting shape on the other side, and it can all run again.
Setup
Four players around the perimeter at the two slots and two corners, one player at a block. The ball at a slot.
Trigger
The ball is reversed to the other slot, which starts the flex cut on the new weak side.
Read
The flex cutter reads his defender at the cross screen: over the top, cut to the rim; under, stop at the block and seal. The screener then reads his own defender at the down screen: chased, curl; under, catch at the slot and shoot. Because the sequence repeats, a defense that guards it well three times still has to guard it a fourth, and the offense is looking for the one repetition where a defender is late.
Payoff
A layup on the flex cut or a jump shot at the slot, from a sequence that can be run until one defender makes a mistake.
Beaten by
Switching both screens, which is easy when all five players are similar in size and hard otherwise; or a defender who goes under the cross screen every time and lives with the seal. Lecture 4.5.
Action 2: Flex: a cross screen and a down screen, and then the same shape again.

3 Dribble drive motion

Dribble drive motion removes the post player from the lane on purpose. Four players stand outside the arc and the fifth waits in the weak-side dunker spot, so the lane is empty from the free-throw line to the rim. The offense is then one thing repeated: drive a gap, make the help defender choose, and pass to whoever he left, as in Figure 4. There are no screens in the base offense, which is what distinguishes it from everything else in this chapter: the advantage comes from the dribble and the spacing rather than from a body placed in someone’s path.

A 4-out 1-in floor: 1 has the ball at the right slot, 2 is in the right corner, 3 on the left wing, 4 in the left corner, and the one big, 5, waits in the left dunker spot beside the baseline, not in the lane. 1 dribbles past his defender x1, who is left behind at the slot, and down the right side of the lane to just right of the rim, labeled drive the gap. x5 has stepped into the lane in front of the rim. x4 stands on the left side between the corner and the lane, labeled he has to choose, between the rim and the corner. Two dashed passes leave the end of the drive, one to 4 in the left corner and one to 5 in the dunker spot, and both run below x4 and x5. x2 is with 2 in the right corner and x3 with 3 on the left wing.
Figure 4: Dribble drive motion. The lane is empty and the big waits in the weak-side dunker spot. The handler drives the gap; the weak-side defender has to choose between the rim and the corner, and the pass goes to whichever he leaves.
Setup
4-out 1-in with the one big in the weak-side dunker spot, never in the lane. Two players in the corners, two above the arc, a double gap on at least one side.
Trigger
The handler attacks a gap.
Read
The driver reads the weak-side help. Nobody helps: layup. The low man helps at the rim: the corner he left is open. The nail defender steps across: the drop-off to the dunker spot. The driver’s own defender recovers in front: the driver retreats and the next player attacks the gap that has now opened.
Payoff
A layup, a corner three, or a drop-off, chosen by the one defender who had to guard two players.
Beaten by
Guarding the drive with one man and never helping, which requires defenders who can stay in front; or a defense that walls off the middle and concedes the pull-up. Lecture 4.4.
Action 3: Dribble drive motion: empty the lane, drive the gap, and pass to whoever the helper left.

4 What the three have in common

None of them is a play. Each is a set of rules that can be run for a whole possession, and a team chooses between them on the basis of its players rather than its opponent. Princeton needs a passing big and patient cutters. Flex needs five players who can screen and catch, and rewards a team whose players are similar in size. Dribble drive needs guards who beat their man off the dribble and shooters in both corners. A team that picks the wrong one runs it badly against every opponent, which is why the choice is a roster decision and not a game plan.

What they share with the set plays of lecture 3.8 is that both must eventually produce one of the actions of lectures 3.2 to 3.7. A continuity is a way of arriving at a cross screen or a back cut again and again; a set play is a way of arriving at one of them once, on purpose, at a chosen moment. The vocabulary is the same, and it is the vocabulary rather than the system that a viewer needs in order to follow what is happening.

One more system has no entry here yet: the swing offense, a continuity built on a shuffle screen from the block to the wing with the cutter posting up. It is described in the dated diff in data/sources/, is named by one publisher only, and gets an entry if a second independent source names it. A fourth system that does have an entry, the triangle, is Section 5.

5 The triangle offense

The triangle offense is a continuity built on a shape rather than on a sequence (Figure 5). Three players make a triangle on one side of the floor, a post on the block, a wing and a player in the corner, and the other two play on the weak side. The pass from the wing into the post is the hub: every player in the triangle is one pass from the other two, so every catch has a read built in, and the two on the weak side are far enough away that their defenders cannot help without leaving a cutter. The pinch post of lecture 3.7 is the weak side’s own hub.

Three attackers make a triangle on the right side of the floor: a post player on the right block, a wing on the right wing with the ball, and a player in the right corner, labeled sideline triangle between the post pass and the corner. The two other attackers are on the weak side, one at the top and one at the left elbow, labeled two on the weak side. A dashed pass from the wing into the post is the entry the formation is built around.
Figure 5: The triangle offense. Post, wing and corner make a triangle on the right side; the other two attackers are at the top and the left elbow. The wing’s pass into the post is the entry the shape is built around.
Setup
A post on the block, a wing and a corner on the same side; two players on the weak side, one high and one at the elbow.
Trigger
The ball reaches the wing with the post established.
Read
Post fronted, the pass goes to the corner for a better angle or over the top; post played behind, the entry, and the wing and the corner cut off it; the post entry denied entirely, the ball reverses to the weak side and the triangle forms there.
Payoff
Every possession starting from the same shape, so the reads come from the defense and not from a called play.
Beaten by
Denying the post entry so the triangle has no hub, and fronting or three-quartering the post so the wing’s pass has to go over the top. Lecture 4.4.
Action 4: The triangle offense: three players one pass apart, and the post as the hub.

6 Names heard for which there is no entry yet

Four more names are given by one publisher each, so under this site’s rule none of them has an entry until a second independent source names it, and the swing offense above is on the list for the same reason. The descriptions are here so the word is not a mystery when it is heard; the rule and the dated diff are in the plan (plan/PLAN.md, section 8.4) and data/sources/glossary_diff_2026-09-22.md.

  • Wheel. A continuity whose repeated unit is a cross screen and a flare screen set in combination, so the floor comes back to the shape it started in and the pair can be run again. It is a near relative of flex in Section 2, which repeats a cross screen and a down screen instead. The glossary that names it says the offense is also known as blocker-mover.
  • Stagger wheel. The same continuity idea with the staggered screen as its unit, one stagger after another for as long as a team wants to keep running it. The stagger itself is taught in lecture 3.5; what this name adds is the continuity built out of it.
  • Point. The opening action of the point series, one of the series the Princeton offense of Section 1 is run from: the trailing power forward sets a down screen for the low-post player, who flashes off it to the opposite elbow. The word names an action here, not the position it shares a name with.
  • Corner offense. An alignment, not an action: three players on the strong side, a big at the elbow with a guard at the wing and another in the corner, and on the weak side a second big at the other elbow and a forward near the slot. The glossary that names it says what it is run for: triangles, backdoor cuts and post-ups, which puts it close to the triangle offense above in what it wants and different in where the players stand.

The idea to carry into lecture 3.10 is that every system in this lecture depends on spacing. Princeton needs its cutters one pass apart, Flex needs its corners filled, dribble drive needs a double gap. The next lecture is about the floor itself: where the spots are, what the alignments are called, and why the distance between two attackers decides what one defender can do.