Stretching to the Limit

The first two games of the Eastern Conference Semifinals could not have possibly gone worse for the Boston Celtics. That's an understatement. They had a 20-point lead in both games, and lost both. That's hard to do, but honestly the way they've played the bigger upset has been that they built 20-point leads. It has been a total team failure, from the coaching to the players. It's hard to find a through line when so many different things have gone wrong, but I think it comes back to the Knicks' length.
First, the Knicks are collapsing on every Celtics drive with hands out to try to slow down drives. In Game 1, the effect was that Jayson Tatum and Jaylen Brown just stopped driving to the hoop. That was not the case tonight, but their success getting to the paint was still not great. Brown had a lot of success in the first half, then disappeared. Tatum didn't have any success at all, shooting just 4-for-14 on two-point shots. It was just the eighth game of his career where he hit four or fewer two-point shots when attempting at least 14. Five of the prior seven came in 2019 and 2020, and the last time was in December of 2023. But for whatever reason, Tatum looked incredibly mortal in both of these games, and that has been a huge problem, because in the regular season, it was his play that really was the separator between these two teams. This is especially frustrating, because it's the old Miami Heat playbook, and Tatum should a) be used to it, and b) is strong enough to power through it. But the Knicks are long enough to be collapsing and reaching and still get back to contest kick-out passes. It's a fractional, small thing, but the Knicks are dialed in on it right now.
The other issue has been rebounding when it matters. Here's a breakdown of the rebounding in the two games thus far:

There's a very, very, very simple and clear reason for this: Al Horford is finishing games instead of Kristaps Porzingis and/or Luke Kornet. In Game 1, the Knicks killed the C's by pulling Horford into screens and making him defend Jalen Brunson in space. They weren't able to hammer on that in Game 2, but it didn't matter, because they beat him on the glass. Three times in the final five minutes, Horford was either beaten for a rebound or wasn't even in position for one because he was roaming, which is not something that Porzingis or Kornet do. None was more damaging than the put back and-one by Karl-Anthony Towns to close the gap from 86-82 to 86-85. Horford got beat, and then made a soft, obvious foul to put Towns at the line. Half a minute later, the Knicks had the lead, after Tatum once again took a difficult shot because New York's length once again bothered him – in this case, OG Anunoby. And yet it's hard to fault him too much for the shot, because everyone else is just standing there:

No one is cutting. Everyone is standing there watching Tatum. If Jrue Holiday or Jaylen Brown cuts to the hoop, maybe the C's get an easy bucket. Instead, they were spectators.
Getting back to the rebounds – it's very clear to me that the C's cannot be letting Al Horford close these games, at least not as the lone big in the game. He played 8:47 of the fourth quarter in Game 1, and then all five minutes of overtime. He didn't pull down a single rebound in that OT. In Game 2, he played the whole 12 minutes. He pulled down two rebounds, but was 1-for-6 from the field, and was a -13 overall.
I love Al Horford very much, but the coaching staff is doing both him and the team a disservice by playing him this much late against this Knicks team. He's not tall enough to bang with Towns and Mitchell Robinson, and he's not fast enough to stay with Josh Hart, Mikal Bridges, and Jalen Brunson. It's just a really bad matchup for him.
That's not to excuse everyone else. Payton Pritchard forced bad shots tonight. Jaylen Brown disappeared in the second half of both games. In the first half of each, he shot 5-for-11 and 7-for-16. In the second half, he shot 1-for-7 in both games, and was 1-for-2 in Game 1's overtime, making him 2-for-9 after halftime in that game. If you're scoring at home, that's 12-for-27 in the first half, and 3-for-16 in the second half. That's not cutting it. Derrick White was 2-for-8 in the second half. Jrue Holiday shot well tonight, but only took six shots, and three of them came in the first quarter.
I think it comes back to the length of the Knicks. Even on the final play, Tatum, who is basically 6'10", thought he had the wherewithal to jump over the defender and get a kick out pass to Jaylen Brown. The only problem is that Mikal Bridges is really long, and with that little time left on the clock, he gambled, and he succeeded:

If Tatum had gotten that pass to Brown, JB has a wide-open shot. If you just freeze it right there, and see what Tatum saw, you can understand the thought process. But Bridges is just not most defenders. He's got very long arms, and even better instincts. This is why the Knicks traded so many first-round picks for him.
That length is forcing the Celtics out of what they want to do, to the point where it isn't even really clear what the Celtics want to do. They seem out of sorts, and are falling susceptible to a Knicks team that is bending but not breaking. It's here where coach Joe Mazzulla is just showing too much trust in his team. He essentially left two time outs on the table tonight. One should have been called at 3:16, after Josh Hart's floater had closed the gap to 86-82. At that point, the C's had three time outs, but were going to lose one when the clock went under three minutes. They would indeed go on to lose that time out without using it. Mazzulla usually does a fantastic job of calling that time out and not losing it. Tonight he didn't.
A little over a minute later, the Knicks had the lead, as his team couldn't do anything to stem their momentum. Perhaps a time out wouldn't have helped, but it certainly couldn't have hurt. He did it again on the final possession. He said postgame it was because Towns wasn't in the game, and Brunson was. He also said it's because he wanted to run the exact same play as he had 20 seconds earlier, which is idiotic. Obviously the Knicks were going to know be watching for that. And when Robinson blew it up, and the C's had no clear advantage with six-seven seconds left, he could have called time out then and set up a play. He didn't.
I don't think the Celtics are lacking effort, or anything like that, but late in these games, they are absolutely not dictating play, and they are definitely not executing. This is twice now that they had the chance to tie the game or take the lead on the final possession and didn't even get a shot off. New York's defense is not this good. The C's need to regroup and figure out how to dictate play against a team they frequently mopped the floor with in the regular season.
I remain convinced that the Celtics are the better team, and will in fact regroup and win the series. But they are suddenly facing a deficit that was completely avoidable, and have squandered an opportunity to have a short series, which is doubly frustrating when it looks like the other East series may also go six or seven games.