You might remember my 1-3-1 post from December, where I set some guidelines about the series. I have a few big concept posts planned - what the zone does well, what it does poorly, how NU's zone compares to other schools that play it - but sometimes something catches my eye, and I'll throw up a post on it. I'll call them quick hitters, in the vein of Sebastian Pruiti from NBA Playbook.
A common statement about the 1-3-1 is that it puts Northwestern at a major disadvantage: why would anybody play a defense where your shortest player is the guy closest to the basket? It seems like common sense that putting a 5-foot-10 guy in the post would lead to defensive chaos as big centers body them on the way to easy buckets.
But I've got a myth to dispel: putting a short player on the baseline works, even against very talented, very tall players.
I'll show two reasons for this: first off, the player assigned to the baseline isn't always playing the post player. His job is to defend along an area of the floor along the baseline that extends from sideline to sideline. A lot of the time, his focus is on shooters in the corners while players from the weak side take care of the post. Secondly, the 1-3-1 defense should never have the baseline defender guard the center one-on-one. As soon as the ball is entered to the post, two defenders immediately collapse in help defense. Lots of times, centers see they are being guarded one-on-one by a little guy and think that their best option is to immediately put up a shot. In reality, there's a defender coming from the weak side and a center coming from the middle of the zone, often leading to highly contested shots.
NU ran the 1-3-1 zone a lot in the first half against Purdue on New Years' Eve, and JaJuan Johson, the team's preseason All-American big man, who averages 19.5 points and 7.6 rebounds. He's 6-foot-10. Michael Thompson is 5-foot-10. Although Johnson would go on to have a fantastic game - 19 points on 12 shots, along with 9 rebounds - he struggled against the zone. I'll show you why - after the jump.
During the stretch of time NU played the 1-3-1 zone, Purdue entered the ball to Johnson six times. I've highlighted three of those plays to show how coach Carmody trusted Juice Thompson and co. to handle one the conference's best scorers in the paint.
Play no. 1
NU came out in the zone at around the 17-minute mark of the first half, down 10-7. On the first possession, they passed the ball around for an open 3-pointer by Ryne Smith, who missed. On the next, they ran what looks like a set play designed to exploit Juice Thompson.
Lewis Jackson brings the ball across halfcourt, and Johnson is posted up on Thompson. Purdue clearly knew their stud would be on the tiny Thompson, and decided in practice a good play would be a quick entry over the top of the zone. Jackson has a seemingly easy pass.
Here's the thing though: it's a pass that will take time to complete. Thompson may be only 5-foot-10, but he'll be able to interfere with a regular chest pass because he's fronting Johnson. The pass has to go over the defense, and the air under that pass will allow the defense to rotate and adjust. Shurna and Mirkovic are both watching the ball and about 10 feet away from Johnson. By the time the ball reaches Johnson, he gathers it, and prepares to score, one of them will probably get to the spot they need to be in to defend a shot. Secondly, lobs are just by nature more difficult to complete than regular passes. There's more variables. The defense has time to adjust to get into position to defend it.
Turns out Jackson's pass isn't much good. Thompson disengages from fronting Johnson and basically goes to where the ball will be, while Johnson is caught sort of out of position and has to try and reach for the ball with one hand, and 't catches the ball just about eight feet in the air - allowing Thompson to get a hand on it.
Not surprisingly, Johnson gets control of the ball over Thompson. But in the time it took him to battle Thompson, Shurna - who was the weakside defender, whose job it was to stay near the basket, close enough to defend either Johnson or the shooter in the corner, Ryne Smith, if Jackson decided to pass to either - rotates and gets a hand on the ball.
Shurna knocks it loose. Luka Mirkovic and Drew Crawford both touch the loose ball, but in the scramble, it comes loose and goes to Ryne Smith in the corner, who gives it to E'Twaun Moore, who was wide-open and hit his third 3-pointer of the game. Yes, the outcome of the play was a 3-pointer, which is unfortunate for NU. But the design of the play was for Johnson, and NU ends up successfully denying him from getting to the ball. Sure, there's a broken play 3-bomb, but luck happens sometimes.
Play no. 2
The next play comes about a minute later, at the 15:14 mark of the game, and it's another designed look for Johnson in the post, this time coming from backup point guard Kelsey Barlow.
Similar set-up to the last play. Again, NU is in the 1-3-1, and Johnson has a fronting Thompson completely sealed off.
However, there's a difference in Purdue's offensive set-up. Last time, Ryne Smith, the potential 3-point shooter, was in the weakside corner, making him Shurna's responsibility. This time, he's on the ball-side, meaning if the ball was passed to him, Thompson would cover him while Shurna sprinted to the paint to make sure Johnson wasn't alone in the paint. This means he's positioned differently: he's up at the top of the key, about halfway between Moore and Johnson. But in both plays, the concept is the same: he has two responsibilities and can't shade towards either. But the one Purdue is clearly hinting towards is the over-the-top pass to Johnson. Shurna positions himself on the weakside knowing he has to be able to reach Johnson by the time he collects a pass.
In this picture, the pass is in the air. (You can't see it - sorry, bad video quality. I think it's the orange splotch over the letter "R" in "Boilermakers" on the sideline in front of the NU bench.) Thompson will have no way of interfering with even a moderately decent pass. But Shurna has already started to move towards his responsibility as a help defender on Johnson.
Shurna needs about three steps to meet Johnson, incidentally, exactly the amount of time it took the pass to get to him. Johnson doesn't dribble, pump fake, or hesitate: he catches the ball, sets his feet, and goes straight up with a layup. Most likely, he does this for two reasons: first off, he knows he's posted up against someone giving up a foot on him and doesn't need fancy moves to score over him. Secondly, he probably knows that help is coming from somewhere, and that he has to act quickly. But it isn't quickly enough: Shurna is right there with him, and blocks the shot as it leaves Johnson's hand, and NU recovers the rebound.
Play no. 3
We'll skip ahead to the seven-minute mark. The design quick-hitting plays that saw lobs from the primary ballhandler into the paint weren't working, so Purdue shied away from them a bit. On this play, Purdue swung the ball around a bit. 
Kelsey Barlow (at the top of the screen) had the ball, which is why JerShon Cobb and John Shurna are so close to him, but he switched the ball to the other side of the court, where E'Twaun Moore is pictured receiving it. A switch always does good things against the 1-3-1 zone: it's predicated on the concept that the zone can rotate in the time it takes a pass to get someplace. However, when you just switch the ball from side to side, sometimes you catch the defense off-guard, because while the zone can handle a single pass - as Moore receives it, he's a little too far out to shoot with Crawford sprinting towards him and Cobb coming in about a second, and although he's a deadly shooter, he's not pulling from 25 feet - it can very easily be beaten by two quick, decisive passes.
Look at the player on the bottom right of the screen, Terone Johnson. He is wide, wide, wide widewidewide open. Crawford had been guarding him when the ball was on the other side of the floor, preventing the skip pass, like Shurna was playing in Play no. 1. Now that Moore has the ball, he has to run out on him preventing him from getting a shot. Thompson is supposed to switch onto him, but he has to stick with JaJuan Johnson until Shurna - who had been guarding Barlow as part of a trap at the top of the zone can run across half the court to the area around the bucket. It would be a tough pass because of Crawford sprinting, but if Moore jumped, he could probably bullet it in there to the unguarded Johnson for an easy layup with Thompson still occupied by JaJuan Johnson.
Moore passes the ball literally as soon as he gets it. As he prepares to let it go, the situation is pretty much the same: although Crawford and Cobb have closed on him, taking away his shot and driving lane, Shurna still hasn't rotated, meaning Thompson can't yet leave JaJuan Johnson to guard Terone Johnson. But Terone isn't doing a good job of making himself available. He's just standing there with his hands up. He's not calling for the ball, even though he's wide open. Maybe he's yelling "hey!" or whistling like some people do when they're open, but it doesn't show on camera.
JaJuan Johnson, on the other hand, is sealing off his man and calling for the ball, and it draws the attention of Moore, who prepares to throw a lob pass much like the ones we've seen in the first two plays. Two quick passes against the zone can do damage. Instead, Moore is opting to throw one quick pass and one pass that will take about a second to reach the intended target. Instead of catching everybody rotating leading to a quick hoop, the defense will once again have time to adjust.
Note Shurna - in the first two plays, he was on the weak-side and came to help when the pass was thrown. This time, as the pass is being thrown, he's already rotating to the person the pass is intended to, since his responsibility after the ball switched sides became the post player so that Thompson could move out on Terone Johnson.
The pass is pretty identical to the one in play no. 1, which is to say, it takes Johnson away from the basket and gives the defense more than enough time to adjust. Shurna is firmly in between Johnson with a hand up, and Curletti rotated as a help defender, with Thompson capable of sneaking in from behind to make a play. Purdue passed into the paint because they saw he had Thompson sealed, which in a one-on-one situation, would be perfect, because he'd just rise up and dunk. But it's a zone: instead of the size mismatch the defense was looking to exploit, Johnson is now being double-teamed by the 6-foot-8 Shurna and 6-foot-10 Curletti. To make room for the play to operate, Terone Johnson has actually had to take a few steps back to get out of Johnson's way.
Like in play no. 2, Johnson goes straight up with the ball, probably knowing that help is somewhere and that he doesn't have time to react. It's not for lack of options. As you can see, the two players Curletti and Shurna abandoned, D.J. Byrd and Barlow, are cutting into the lane. However, rather than hit them with the pass, Johnson thinks quickly and goes for the shot hoping the pass has caught the defense off-guard on their rotations. It hasn't. He hasn't noticed Curletti coming from behind him, and Curletti smothers the ball with his upper arm - to be honest, I think he gets some armpit on the ball after having watched it about eight times (although Shurna incorrectly gets credited with the block). Like play no. 1, this play doesn't have a happy ending: the ball looked like it was going to fall either out of bounds or into Shurna's hands after the block, but it catches a little bit of backboard and bounces right to Byrd cutting who lays it up and in. Again, great defense, unfortunate outcome.
Conclusion:
Like I said earlier, Purdue entered the ball to Johnson against the 1-3-1 six times. (The possessions you didn't see: a floater-ish thing blocked by Drew Crawford that I didn't include because it came off an out-of-bounds play and didn't strike me as typical of the 1-3-1, a jumper over Juice Thompson from about ten feet out, and a and-1 layup when one of the lob passes actually beat the defense's rotations.) On those six possessions, Johnson was 2-for-5 for five points and was blocked three times, with one loose ball he never got control of. Meanwhile, against the matchup zone, where Davide Curletti and Luka Mirkovic were assigned to guard him one-on-one basically, he went 4-for-7 and took eight foul shots, ending up with 14 points. NU switched away from the zone in the second half to respond to the fact that it was frequently leaving E'Twaun Moore wide open and he was obliging the Cats by draining shots, but against Johnson, who is easily all-Big Ten this year, the 5-foot-10 guy did his job. Johnson wasn't an easy target for his passers, and when he got the ball, made the poor decision to put the ball up immediately in hopes of beating the help without realizing that it was already there. Dallas Lauderdale, Ohio State's enormous, but completely offensively untalented center, can score by catching the ball and putting it straight up. So can Johnson, when his shot isn't getting blocked. However, Johnson, unlike Lauderdale, can score in other ways. He has post moves galore, he can shoot, or body people while maintaining a dribble. Even if Johnson didn't get blocked, but was merely bothered, on his three unsuccessful shot attempts, putting the 1-3-1 on him took away what makes him special: he's a great scorer, and instead of using that talent, he just caught the ball and hoped he could put it up fast enough to score. However, the help was there, and he was swatted on all three attempts.
I get the sense opposing coaches and players see Juice Thompson at the bottom of the zone the same way the average NU fan does. Jesus Christ, he's playing in the paint? Our big guy should go crazy down low. I get the sense JaJuan Johnson watched tape and thought he would have a field day against the little guy, and judging from his teammates' willingness to pass to him in the post, they thought that too (and I'd bet Matt Painter advised they look to him down low as well.) They passed up better opportunities - like a wide open Terone Johnson in play no. 3 - and Johnson went straight up, hellbent on scoring over his smaller opponent.
But it's a trap. On the six possessions, only once does Johnson actually get one-on-one coverage on Thompson. Yes, he got a 3-point play out of it, but a 1-in-6 success rate to me sounds like somebody being taken out of the game. The 1-3-1 zone makes you think that Thompson will be a liability. In fact, against Purdue, the way players closed in on Johnson in the paint made plays to him significantly less efficient than they were when he was being guarded straight up by a big man.
And, yes, in actuality, those six possessions ended up with 10 points, thanks to the loose balls that ended up in Moore's and Byrd's hands. To me, that's not the point of this exercise. NU's defense held JaJuan Johnson and he performed at a level less than the one he normally performs at, and considerably less than he performed at against the matchup zone, even though the overwhelming majority of people who see NU games comment on how putting players with such a huge height disparity is a major disadvantage for NU. Some loose balls fell into the wrong hands? That'll happen sometimes. None of the plays against Johnson were because of NU being lucky, they happened because x's and o's dictated that they would happen. Once they did, guys were out of position when a freak ball bounced the wrong way. That's the game.
So, conclusion: putting a tiny guy against a big guy is not what it seems. It helps goad the opposition into feeding their big man, even when doing so will actually end up with him forcing a lot of bad shots. If anything, the thing that will put NU at a disadvantage defensively against big men is how bad Luka Mirkovic and Davide Curletti are at man-to-man defense, not Thompson's diminutive size - but that's a million posts for another time.