Exploring the Boston Celtics Slice Actions
The Boston Celtics Slice Screens
Every coach has their go-to plays. Every system has a set amount of screening actions that become core concepts throughout the season. Joe Mazzulla's Boston Celtics team is no different. As the playoffs get closer, we'll undoubtedly look at more of these concepts and actions in greater detail. But, for today, I wanted to dive into the Celtics "Slice" actions.
A slice screen is simply a back screen set for an off-ball player (usually, you'll see me call these "rip screens") on either wing. The thought process behind these is simple.
They can create a mismatch, as the screen receiver often gets switched onto the screener's defender.
They allow the screen receiver to get to their spots.
They usually lead to a post-up or a stampede cut, where a player who is already cutting receives a pass and then attacks the rim.
Mazzulla likes to run this action on sideline-out-of-bounds (SLOB) plays. However, the Celtics do use them in the halfcourt, too.
In the above clip, Jrue Holiday is the one to set the slice screen for Jayson Tatum. Notice the confusion it causes for the Washington Wizards. Holiday is a genuine scoring threat. He's also operating as an inverted screener (where a smaller player screens for a bigger player.)
Notice how Jordan Poole gets a little bump on Tatum as he cuts off the screen? That's called "tagging" the roll man or "tagging" the cutter. It's designed to momentarily slow down the roller/cutter so that the help defense has an extra beat to rotate over. In this instance, though, it didn't work. So then, the question becomes, why did this simple screening action tear open Washington's halfcourt defense?
It all started with the initial entry action. The Celtics flow into what looks like a modified "21 reset," which is usually but not always a guard-to-guard hand-off on the wing, followed by the hand-off receiver passing the ball to a big man at the top of the perimeter, aka "The Delay." Kristaps Porzignis then triggers a second-side action by passing the rock to Derrick White.
Now, the weakside action begins. This is where the slice screen takes place. And it's why the entry pass is so important. White only has one defender on his side of the floor. There's an empty corner, so there's no low man to rotate or pressure the passing lane.
Poole's decision to tag rather than stick with the cut is what sets Tatum free to get into the paint. There's no low man on the other side of the floor to rotate over. Tagging, in this instance, was essentially a pointless exercise. So, White makes an easy pass from a perfect angle.
To help illustrate this further, here is an annotated version of the play.
As you can see, there are a lot of moving parts in getting a half-court set to go as planned. The defense can react and blow up the entire action at any point. In this instance, that likely would have occurred in one of two places.
Either the Wizards' denied the initial hand-off between Tatum and Brown, which could be by top-locking Tatum or sliding in between the two players to kill the hand-off. Or, they could have defended Tatum's cut better and fronted the post. From there, it would have been up to Boston to counter that coverage. The most likely response is an empty side PnR between Porzingis and White or Brown bully-driving toward the nail or mid-post for a pull-up.
That's probably why Mazzulla prefers to run these sets during SLOB situations. There's less room for the defense to counter. You're attacking a set defense in a more confined situation. Generally, Boston runs these slice actions for Tatum. However, against the Wizards, they did put Porzingis in the action while the All-NBA forward caught a breather on the bench.
Here's the example of Boston's SLOB Slice action from the Wizards game. Notice how simple it is to run? It's an inbounds pass, the slice screen, and then an entry pass. That's it. Sometimes, the most effective plays are the simple ones. The Celtics convert on this action most of the time. A key point to note here is that the inbounder is always the one to receive the slice screen, which is set directly off the inbounds pass. Here's another example, this time with Tatum being the recipient of the screen after setting an inbounds pass.
This play had one extra step in the sequence due to how the Indiana Pacers defended it. Aaron Nesmith trailed Tatum's cut until he was picked up by Tyrese Haliburton. So, Holiday fed White after the screen, and then he made the post-entry pass to Tatum, who had a mismatch with Haliburton, and then, well, you know the rest.
Here's another example. Similar concept. Entry pass out of the SLOB. Slice screen. Defense guard well. Pass to the screener. Post-entry pass. This time, Josh Hart defends Tatum well, forcing him to score out of the post rather than allowing him to get to the rim.
In part, that's why Tatum is usually the recipient of this action. His post-scoring has dramatically improved. He's a genuine threat in those situations. And he has the playmaking and processing speed to make high-level reads when his shot isn't available. It's also why we will likely see Porzingis in these situations more. His height and post-scoring abilities allow him to be an advantageous weapon for the Celtics during these situations.
Slice screening actions have become commonplace within the Celtics system this season. They're working well and have a high conversion rate due to the slashing, post-scoring, and physical talent on the roster. Here's an example of how you can counter the defense when they take away the slice action.
Notice how the Celtics flow into a high PnR after the defense has killed the slice action. That allows the ball-handler, in this instance Brown, to drive the lane and either make a play or kick out to a shooter. Brown has been exceptional when bullying his way to the rim this season, so it's no surprise how this possession shook out.
Slice Screens vs. Wedge Screens
I, like everyone, am still learning. Earlier this season, I consistently mixed up slice and wedge actions. They're both similar screening actions, happen in similar areas of the floor, and often look alike. Yet, they're designed for different outcomes.
While we're focusing on slice screens, I thought it would be prudent to point out the differences between the two types of screens. And if this is the first time you're encountering wedge actions, then it's additional upside, right?
As I mentioned earlier, a slice screen is a back screen for an off-ball player on the wing...A wedge screen is a diagonal screen set for an off-ball player to get them into the post, usually on the opposite side of the floor. Another key aspect to note is that a wedge screen usually occurs on - or near - the elbows. The diagonal positioning of the screen is key.
The above clip shows a wedge screen from White. He is positioned diagonally. He has cut toward the screen in a diagonal line. The screen occurs around the elbow. Tatum gets to the paint but could have posted up on the strong side if the defense had played him better. Wedge screen. Another key aspect is how the wedge screen is always facing a sideline, usually the one opposite where you want the player to cut.
Go back and watch the first clip in this newsletter. Holiday's screen occurs at the elbow. It gets Tatum into the post. Yet, it's not set via a diagonal cut. And the screen is angled at the back of the defender, not diagonally toward his hips...See how easy it is to mix these up?
It drives me crazy. And, in the grand scheme of things, the naming scheme doesn't really matter. The important thing is that you can see the play occurring and understand how the advantage was created. Naming the play is a bonus. A bonus that I'm still working toward learning.
The plan for this week.
The trade deadline came and went. We have two new players on the roster. Hopefully, we can see them on the court in the near future. However, the Celtics still have an open roster spot. They will likely look to add another talent via the buy-out market. Or, they could turn toward Neemias Queta by converting his contract – yet, with Xavier Tillman's addition, that makes little sense to me. Whatever, Brad Stevens knows more about basketball than I ever will; whatever he decides, I'll trust.
Still, it's fun to look at potential targets. I'll be embedding some YouTube videos that we produce over on the Green With Envy podcast in the coming days, looking at different buy-out options. I'll use the newsletter to take a close look at how some of the more logical additions could fit into the system and where they could add value.
I also want to do a dive into Jaden Springer. Ideally, I would prefer that to be based on what we see from him on the court. We will have to wait and see how that plays out or whether pulling footage from his time with the Philadelphia 76ers is more prudent.
If you're looking for an overview of what Tillman brings to the roster, I took a look at that for CelticsBlog.
As most of you are probably aware, I write up the 10 Takeaways after every game over on CelticsBlog. I'm trying to think of something I could do after games for the newsletter. The issue is that the takeaways take a lot of time, so I don't want to rush what I'm putting out here. As the newsletter grows and the income becomes sustainable, I'll have more time. But, I'm open to suggestions, let me know in the comments section.
That's it for today! I'll be back again early in the week. Enjoy the early tip-off against the Miami Heat. Hopefully, the Celtics can get the W and keep building some breathing space at the top of the Eastern Conference. Again, if you do decide to kick into the tip jar, thank you, it truly does help.
Catch you all later! Enjoy your Sunday!