Who guards who in the Raptors-76ers matchup?

The first round is still technically ongoing, but the second round of the NBA playoffs begins in earnest tonight with the matchup between the Eastern Conference’s No. 2 and No. 3 seeds, the Toronto Raptors and Philadelphia 76ers.

These are two teams that have spent the season progressively one-upping each other with all-in moves. First, the Raptors swung a trade for Kawhi Leonard. Then, the Sixers made a big move for Jimmy Butler. They made another splash for Tobias Harris. And then the Raptors responded by getting Marc Gasol. Now, the Atlantic Division rivals will square off for the right to advance to the Eastern Conference Finals.

It’s difficult to draw much meaning from the regular-season series between the two sides, which Toronto won 3-1, because the first of those four games took place before the Butler trade, the Sixers’ win came in a game where Kawhi Leonard sat out, and all four contests were already played before the Sixers acquired Harris and the Raptors acquired Gasol. It makes much more sense, then, to look at this series of what makes it most interesting; and to me, that’s figuring out how the Sixers will match up against the Raptors defensively when each team has its five best players on the floor.

Only one matchup seems so obvious as to rule out any other option: Joel Embiid will guard Marc Gasol. Gasol is a bit stretchier than the Sixers would like and that will draw Embiid farther out on the floor than usual, but it’s not like stashing Embiid on one of Toronto’s other starters is going to keep him any closer to the paint. And the Sixers can’t risk Embiid either being too far away from the rim or getting into foul trouble by having him guard someone else. How Brett Brown and company decide to match up from there, though, is up for debate. There are merits and drawbacks to several different configurations, but it may be best to look at them from the perspective of the different options the Sixers have against Toronto’s other starters.

Any consideration of said options has to start with the question of whether or not Tobias Harris can stay on Pascal Siakam. If he can’t, that’s when the Sixers have to start cross-matching, and things necessarily start to get a little weird.

Harris defended Siakam quite a bit during the two Raptors-Clippers matchups this season, and those possessions did not go well at all for LA. According to the Second Spectrum tracking data on NBA.com, Siakam was unusually aggressive when being defended by Harris, shooting about 40 percent more often than usual. While he himself did not shoot all that well, the Raptors smoked the Clippers during those minutes, to the tune of 139.3 points per 100 possessions. The sample is tiny and with another team, of course, but the data that exists is not great.

Siakam’s frenetic energy is an odd match for Harris, who often took the less challenging forward matchup than Danilo Gallinari during his time with the Clippers and has been afforded a similar opportunity with Jimmy Butler and Ben Simmons on board in Philly. The less challenging forward matchup for Toronto actually is Siakam, though, because Harris is not equipped to guard Kawhi Leonard. If Siakam’s speed is too much for Harris to handle, the only other hiding spot for him is Danny Green, but having to go that route would force Philadelphia into some unenviable contortions, so they’re likely to at least try to stick with Harris on Siakam for as long as they can.

That configuration leaves Kyle Lowry, Danny Green, and Kawhi Leonard to be defended by Butler, Simmons, and J.J. Redick. Again, there are several different routes the Sixers can go here. In the one game these teams played before Philadelphia acquired Butler, Robert Covington guarded Lowry for almost the whole game. He’s obviously not on the team anymore. In the three games after the Butler trade, he and Simmons spent more time on Lowry than anyone else, though both Redick and T.J. McConnell took turns on him as well. And while the Sixers have generally been better defensively when Simmons guards point guards than when he checks players at other positions, that was not the case with Lowry.

He’s the exact kind of point guard Simmons struggles with most — small, shifty, able to change directions far quicker than Simmons due to their size difference, and capable of both pulling up from 3 or floating a soft runner over the top of bigs in the paint. It’s perhaps not surprising, then, that Philadelphia’s defense was actually at its best when Lowry was guarded by Redick, and at its worst when he was guarded by Simmons. (Though, again, there is a small-sample caveat here, as well as the caveat that all three games were before Harris’ arrival in Philadelphia.)

Shifting Redick onto Lowry, though, comes with its own problems in this series.

First of all, Redick is hardly the team’s best defender; and using him on a point guard as capable as Lowry is probably not the best use of defensive resources, considering Lowry’s role in Toronto’s attack. Additionally, using Redick on Lowry opens him up to being switched onto Leonard or Siakam far more easily, as he would be defending Toronto’s primary ball-handler and thus surely tasked with switching onto the screener on occasion.

Asking Redick to defend Leonard is essentially a non-starter, and the more layers you can put between the two of them, the better. Even having to set one extra screen could shave a few valuable seconds off the shot clock, closing off avenues that might otherwise be open. Hanging with Siakam is a bit more reasonable for Redick simply because Siakam’s not as strong as Leonard, but he has developed a nice face-up and back-down game against smaller defenders this year. Redick would likely not survive that matchup for too long, either.

The only non-Lowry player Redick can reasonably guard, though, is Green, and as mentioned, if Harris can’t stick with Siakam, that’s also the only other player he can guard. Only one of them can guard Green at a time, though, so either Redick has to guard Lowry or Harris has to guard Siakam. Or both. But there’s no sensible alignment that sees someone other than Redick guarding Lowry and someone other than Harris guarding Siakam. It can’t work. (Because neither one of them can guard Leonard, obviously.)

And it’s not as though whichever of those two guys is stashed on Green is going to be able to coast, either. Green’s technically Toronto’s least-threatening perimeter player when they have the starting lineup on the floor, but he is also an elite outside shooter who has worked hard to make his trigger faster and faster over the years, and who has flashed more skill in the post and as a screener this season than at any time in his career. This is not your slightly older cousin’s Danny Green. He’s got more in his bag of tricks than he used to.

Still, in an ideal world, the Sixers would likely have Redick on Green — even if only because that would force Toronto to involve Green in primary actions in order to target Redick on switches, which would by default mean Green was not spacing the floor for Leonard or Lowry. If their ideal world sees Harris holding his own on Siakam and Redick guarding Green, that means Simmons and Butler would be left defending Lowry and Leonard.

How the Sixers choose to approach those two matchups will tell us a lot about what kind of series they want this to be. They’re likely to shift between those matchups anyway given the number of Lowry-Leonard ball screens we’ll presumably see throughout the series, but there’s still a choice to be made. Do they want Simmons to try bothering Leonard with his height and length; or do they want Butler to try bothering him with physicality? Neither option is necessarily all that appealing, because of course, Leonard has counters for both.

Butler is the better individual defender of the two players and it likely makes sense to put him on Toronto’s more important scorer (Leonard), but there is merit to the idea that the Sixers might be best served with Butler primarily on Lowry and Simmons on Leonard. Lowry is a far better creator for others than Leonard, and using Butler to cut off that part of Toronto’s attack could prove very useful. Again, Simmons was not very successful in this area during previous matchups. Doing so might force Leonard into acting as more of a playmaker, something that’s not necessarily his forte. (Though the Raptors could also turn to Siakam as a ball-handler and playmaker if that doesn’t work out.) Having Simmons on Leonard would also leave Philly at less of a size disadvantage if and when it has to switch pick-and-rolls involving Leonard and either Siakam or Gasol. And since Toronto is likely going to have Lowry guard either Simmons or Redick rather than Butler, the Sixers using Butler on Lowry would provide the opportunity for them to get the occasional cross-match in their favor on the other end.

All of this might sound like we’re getting too deep in the weeds, but with two eclectic teams like these, it all matters. How these matches and cross-matches take shape and shake out will determine what kind of series this is, and ultimately, which of the teams wins it.